Firstly, run straight forward and look downwards at the first executor. Shoot as soon as you can then pull right slightly to zap the other one. Ideally this should be done in two fast shots about a second apart - in practise three shots in 1.5-2 seconds will suffice.
Whirl left and left-strafe for the corner of the observatory, switch to unarmed as you slide along the side, jink around the small corner and hug the inside wall as you let-strafe onwards. Mind the small outcroppings on the walls. Jump off the edge at between 0:10 and 0:11. You should already be strafing a good distance along the next wall before you hit the ground - hug it!
Zoom along hugging the corners as closely as you dare and when you get to the T-junction don't even look where you are going as you head left. Blue walls should blur past your vision and once you enter the sniper area at 0:20 or less. Aim so that the stairs you're aiming for are JUST offscreen to the left. Speed-strafing does not take you straight diagonally! With some knowledge, experience and skill you can judge exactly when the steps come up on the left and dive up them (still left-strafing - you left-strafe all the way up to this point). You may get a boost from the sniper at this point.
As you reach the top of the first flight of steps spin the joystick right a bit and switch to right-strafing like lightning. Go up the steps, steer the joystick left so that you hurtle straight across the balcony, then let go of the joystick and hit B with your left thumb as you pass in front of the door. Move your thumb back instantly and steer the joystick still further left and direct yourself down the middle of the door. You should still hold C-up and C-right throughout this whole manoeuvre, opening the door at 0:27.5 or thereabouts.
Twist down the stairs and bolt diagonally across the hall at the bottom towards the blue corridor. Dive along this and the next, strafe across the lounge dodging left slightly to avoid the couch. This is your first chance to grab a CMP-150 - sometimes a guard is positioned in the middle of the lounge for some reason. Disarm him if he comes near you. Spin left down the stairs... still holding right-strafe.
Downstairs, again, you need to know exactly what direction speed-strafing sends you so you pass the corner of the curved wall in the right place. You may also get a second chance to grab the CMP-150 from the guard here if he runs across into your path. Swirl the stick left a bit more and aim for the door. Let go of the stick as you bolt for the door and hit B as you pass the left edge it. Your thumb should be back on the stick as you reach the middle of the door and turn left slightly to dive through it. Go right and zoom down the inside edge of the stairs, and just before you land on the ground at the bottom (at 0:41-0:42), switch back to left-strafing. Smack B with your left thumb once more as you reach the big doors - it's easier because the doors are bigger - and left-strafe in and along the tunnel to the panel area.
Cross the threshold between sand and steel catwalk at around 0:45-0:47. The guard between the two panels is a pain if he runs in any direction except right - if he gets in the way, and you still have no gun, you could try disarming him. Since you're left-strafing, switch to right-strafing at the turn in the catwalk and go straight across to the far panel where you should hit B. Then left-strafe away and hit B again as you pass the second panel - listen out hard for the beeps as you hit the panels to make sure you got them. Turn, and right-strafe all the way back along the catwalks to the first corner in the sandy tunnels.
At this corner a bunch of guards will have caught up by now, and this is your fourth chance to nab a machine gun. Knowing exactly where they are gonna be, hit Z - you're still on Disarm, remember - to steal one of their CMP-150s as you dash past.
Switch back to right-strafing at the next corner, switch to the CMP-150 if you have it during this briefly peaceful moment, and continue to right-strafe to the final panel. Check your clock - 0:55 is what you should be aiming for here. Activate the panel as quickly as possible from side-on and turn around and RIGHT-strafe back in the opposite direction.
Here's your fifth and last chance to grab a CMP-150: the last guard before the lower basement. If this fails you're up the creek and you might as well quit. Disarm him as you pass on the outside, then hit A to switch to the CMP-150 as soon as possible in preparation for the first shock trooper. Stab B at the door as you switch strafe directions, and then left-strafe through. As you bounce down the steps the "Windmill activated" sign will vanish and you can check your time - 0:59-1:01 is the target.
Open fire with your CMP-150 along the right wall of the right-hand tunnel to blow away the first shock trooper, and run through him without slowing AT ALL. DO NOT reload now. You should have over 20 bullets left as you strafe to the next two shock troopers. Stay as far away as possible from them to save time, and shoot the left one first. Just spray at about chest height and you're guaranteed a kill since it's Agent. This bit should take a minimal amount of time.
Right-strafe away down the corridor reloading as you go. Pass the upward-leading corridor at 1:04-1:07. Head for the far door and turn to face straight forwards as you open it and spray the trooper ahead of you. Turn right and run around the right-hand side of the wine rack, spraying the second trooper wildly before you pass the rack. If you're lucky you'll get him. You might even catch his ammo. Hit pause IMMEDIATELY after you shoot the second trooper, select Unarmed and then CMP-150 from your inventory to reload nice and quickly. Zoom on.
The next trooper should be shot while you wait for an instant at the corner, then turn around and strafe so that you can shoot the next one in a similar fashion. This particular shock trooper is a nasty one - sometimes he runs away making your job easier, sometimes he crouches with his face in the wine rack, making it very tough. Then the next one is the most random in his positioning. If he's behind the wine rack shoot him through the bottles. If he's moved, run and shoot him as you pass the corner, WITHOUT slowing down, but making sure you keep at least four bullets in reserve. He can be in any number of places. Ideally he is in your path but many times he's hiding right behind the corner in wait for you. It's a lottery.
Finally, pass the last wine rack and pray to the gods of gaming that when you empty your magazine at the last shock trooper, at least two of the bullets hit him hard enough to kill him and make him drop the keycard. Run through his collapsing corpse and then turn and open the door, backing off so it opens smoothly. Assuming, of course, that you managed to not leave any troopers wounded behind you. :)