Assuming you have a pop-top the first thing to do is to remove:
- the white rubber trim from front of the pop top opening
- the front cab light and the earthing screw just behind it (the two rivets by the side of it should stay)
- any other screws holding the cab headlining up including the screws holding the bunk in place that go through the headlining
- the two aluminium joing strips (where the cab headliner meets the two small bits of wood headliner).
Then you need to get the middle of the cab headliner to bow in the opposite direction to the curve of the roof - just push your hand bewteen the roof and middle of the headliner and push down till it bows. Then it's a case of getting the edge of the headliner out of the channels, one side at a time - you should be able to pull it out with your hand starting at one end and working to the other, though it was pretty tight on mine. With any luck you won't damage it as you get it out - I was replacing mine anyway so wasn't too worried, but I think it was in worse condition after I got it out than before.
