The side pieces
5 or 6 ribbed plastic plugs and 2 screws lower down.
Headlining
2 screws at the rear of the roof.
Put adhesive on the rear part so it sticks to the underside of the sunroof tray.
Apart from that the 3 Jesus handles,the 2 screws and round plastic washers at the drivers side,the door rubbers,sunroof aperture seal and interior light console are all that hold the headlining up.
I had a go at mine,made a mess so sent it to a trimmer who also made a mess so bought a headlining from gary at rs breakers in Portsmouth and was happy with what I received.
Now fitted and looks a million times better that the saggy headliner I had before.