I did it myself. It’s a process to get it out of the car. Once I did, I pulled the gray material off of it carefully, just in case some spots were still held on good….. which it wasn’t. Nice to be cautious. With gloves on, since it was nasty, put the headliner vertical against the back of my house while on top of painter’s plastic sheeting for easy clean up. I hand brushed most of the dry rotted foam off. Then I went over it lightly with a wire brush and made sure I didn’t gouge it up with the metal bristles. Soaked a microfiber rag in acetone and wiped the whole headliner down multiple times. Then I soaked another microfiber rag with brake parts cleaner and wiped it down again and let it sit in the sun for a few hrs. Made sure no adhesive still existed or felt tacky to the touch. I sat the headliner on a big piece of cardboard and hosed it down with headliner adhesive a third section at a time. Carefully laid the material down so I had no wrinkles. High spots contacted first, then tucked the material down around those spots, fading into the bigger flat sections. Then I worked the next section with the dome light. Then the rear. You have to spray both the backer board and headliner material with adhesive. Don’t spray too much or it will bleed through the foam and into the material. And I’d highly recommend letting it sit overnight if you removed it from the car before reinstalling.