the material is on basically cardboard panels which attach to the inside of the door. The haynes manual tells you how to take the panel off. but I'm bored, so I'll explain it...as i've done it several times to replace my door speakers.
Tools: a rag, needle nose pliers, & a philips screwdriver.
step 1: open the door and locate the screw in the door handle (to open it) and take it out.
step 2: in the plastic handle, look under it, there's two large phillips screws in there, take those out.
step 3: (if equipped with manual windows) take a rag, like a washcloth and slide it between the arm of the window...roller...upper thingy... and pull back and forth, you'll see a little U shaped metallic pin start to prop up. grab it with your pliers and pull it out.
step 4: there's little plastic things that hold the panel onto the door, don't be afraid and pull on them. they'll snap snap snap.
step 5: after you get that off, take the door handle and turn it sideways and slide it through the opening so that it'll release from the panel.
The panel might be a little hard to get off, but you'll have to pull up be careful but do it hard, it'll snap out as well.
Once you get the panel off you can replace the material with whatever you want.
I do interiors. I have my own shop and I have a 93 Escort 2 door. I am going to post a step by step with pics on how I redid my interior. I will also show how I fit a 94 GS300 (Lexus) dash and center console with working guage ccluster in my scort. If you're afraid of resin, fiberglass, and body filler don't try the dash thing. Well I should be finished in about two more weeks and I'll probably put the pics on cardomain.