slide the roof back about half way and you will see two clips about a couple of inches in from each side, which clip onto a capstain type pin thing, they are kinda spring loaded clips and to be honest cant remember whether you pinch them together or prise them apart, but when you see them it will be obvious, then just slide it back a bit, then close the roof, and tilt it, you can then remove the lining from the back of it via the tilted open part. Getting it back in again is a proper PITA
buy lots of plasters and have plenty change for the swear box, and dont count on being able to pick your nose after as you will break all your nails, but hey its fun
oh and thats for a D2 S8, not sure what yours is?