HOw hard (or easy) is it to install a headliner in a 68 bug? My (ahem) classic had Carpet(!) on the roof from some "customizer" with what appears to be the original vinyl around the windows, and doorposts etc. How much material comes with your basic headliner kits? Do you need to remove the windows to do it properly? I felt real comfortable last year replacing a bad cam (long story), but screwing up a 50 or 60 dollar headliner kit scares me to death!!