1- Slide this part off first, it'll come out towards you. If you take the bits out in the order they're numbered it'll be easier.

2- Once part 1 is out, just unclip part 2 from all edges (mainly bottom). It'll come out without much hassle

3- (will get more pics to explain this part!!!)

4- These parts are very tricky to take out without breaking the back mounts on them. Basically they're meant to slide down and out towards you but if they don't come out easily and you do break the mounts then just use double sided sticky tape (like the one to hold number plates up) and that'll do the job just as well.