I was gonna help a couple friends do their 4th. I have only done 1 CUASE I HATE THEM, they're annoying and long. I went all the way to the 4th floor but they couldn't join me.

What do I need to do to be able to carry friends 4th ascendancy? What are the steps.

In the mid section room where you choose room, before the boss. Just press leave trial and invite your friends, then open the sekhemas main gate again and you all go in, they stay in the selection room, you continue on to the boss room and kill the boss.
Really simple.

FML so going one room before the boss doesn't work?

No, they wont be able to enter the main gate.