glitched or glitchless? if it's the glitchless route I wouldn't recommend that skip when you're starting out, but Footi would be the best one to explain it I tried to learn it a while back and only got it right a few times and it doesn't save that much time

First about setup, u gotta climb up very left on the second highest step, take step forward and then turn. It's important that when u start moving u only tap forward and after lara lands on lower stair u hold forward again and jump. The jump itself is quite tricky one. After that it's pretty much just grab timing. U have to grab really late, l'm not sure if it's last possible frame but it's really precise grab. And as Beckski said l wouldn't recommend it at all, saves very little time with a save.

Don't be afraid to ask if u have more questions :D If u are interested there's Tomb runner discord where u can get answers really fast or DM me or other runners https://discord.gg/jV6GNqz