Timeline : 64 ticks = 0s
128 ticks = 27s

1 Take a coffee and open your practice server
2 Go Dust II and fly to short
3 Hug the left wall and press SHIFT+W until you see half of the red pannel
4 Aim on the left of it, and aim down till :
-64 ticks ==> your crossair reach the 1st and 2nd stair jonction (cf video)
-128 ticks ==> your crossair reach the "middle" of the second stair (cf video)
5 Run, and just before hiting the box, jumpthrow!

Voilà!