I tracked down some instructions for dismantling this model.
Using a tiny screwdriver and the blade of a knife, prise off the "boot" cover. This is a plastic part located by two pins inserted into the main casting and secured by dabs of glue. It came off quite easily revealing the screw beneath.
At the front, there is a similar panel forming part of the windscreen moulding. Gently prise it off from the bottom. Be careful as it may fly off. It has been known to crack up the middle but may not break completely. Clearly, great care is needed with this part.
Once these two panels are off and the screws behind them are undone, the chassis and seats fall out. The side windows are held in place by the seats so can now be pushed inwards and removed. The back window is a little more tricky as the four clips holding it place all need to be loosened at the same time.
The ceiling panel is plastic so needs removing before using paint stripper. IT is possible to get the end of a tiny screwdriver under it about halfway along and prise it off. It is located at three points along its length and secured with dabs of glue.
The headlights and tail lights have clear plastic lenses located by pins into the main casting. Clean them off on the inside then gently prise them off from the outside.