First off [welcome]!
To answer your question. It is pretty straight forward.
The silver piece that goes around the stereo will pop off. Take a flat head screw driver or a panal remover(if you have one), and stick in crack along the outer side of trim. Pry(gently) and it will start to pop off. Then you will have something like this:
There are 4 bolts that are 7mm holding the stereo in.
If you need anymore help, feel free to ask.