1. Set crouch (L2) to "toggle" instead of "Hold". To do this pause the game and go to controls (advanced).
2. Exit out (keep controls)
3. Then crouch and have the left analog to the right.
4. Press R2 and O at same time. (It'll look like you're standing if done right)
5. If you are unsure try sprinting by press L3 and forward.

WARNING: excessive glitching may resualt in ban.