For first jump, try to run as long as possible on the window ledge. While gliding, hold crouch and when you make contact with the pillar you unchrouch to get on top of pillar.For the second jump you jump to the side of the box and you glide. Then you want to crouch and uncrouch to get a little boost up, while gliding. Then you want to press crouch one more time to get on top of the box.

https://reddit.com/link/kq9uza/video/q98tjpavtb961/player