1993 Ford aerostar

how do i remove the hydraulic that holds the back door open. I’m trying to install new seat belts and i need to take that off to get the panel off.

Support the door before taking off even one gas strut, it’s heavier than you think. Use a broom stick or 2x4.
The little ball stud should have a wrench hex and unscrew like any bolt, with it still in the strut.
The gas strut is just held on with a spring clip and pry off with a small screw driver.