Hello,
Generally you would just say hi in this section and then put your problem in the freelander section. You will get more answers then.
I don't have a freelander, but if it is anything like any other car I have had you will need a tool that slots into the 2 holes on either side of the stereo. Then you push them slightly apart and pull out.
I tend to use kebab skewers, but a proper tool is probably easier!