simplytaboo8

saw another thread where I was told to pull a FONZ....well I hit by the speaker while pushing the up button and finally got it to work...... it was rolling up crooked something awful, motors good, switch is good, etc.
I was getting ready to take the door panel off, but looked on here first. There looks like some white sheeting on the inside of the door covering access to the track...... how do I take that off?
one post said I needed to get a new rivet and gun it in?
I don't have a rivet gun, just basic tools.
can anyone help? thanks!