Glitch jumping[SOLVED]

i know the way your supposed to do it by holding W and S and jumping and you can get on boxes that you normally couldn't get on, so when im in mutation i see someone go up those boxes where BL spawns in Port, i try doing it but i just cant...

so basically i want to know how to get up on those boxes at MM port.

you look straight up at the boxes and you jump and when your at the top of how high you can jump you crouch. See if that works.