If you're inexperienced at this type of thing leave it alone.

Stereo is a pain to get out if you're not competent and will need to have the correct keys - some of the poorer versions will require taking the locking mechanisms apart to remove the keys from the stereo and some of them wont release all pins so you may end up stuck with keys in the dash.

It will need a stereo lead to function properly but again if you're competent all connections are available on the back of the stereo including mute - if using a lead be careful to put the remote controls back into the new connector on the back of the stereo.

If it's going in a mondeo and you have the lead its a 25 min job including locating the microphone and an hour if you've never really done it before - Glove box comes out and side panel off the central console to give you easy access and loads of space.



Primastar

If I remember correctly - if the dash is like this http://www.zebravehicles.co.uk/phase-3-primastar.html you're better off going behind the instrument cluster as I don't think theres room behind the stereo.

It will all be torx screws and phillips anyways and as its a van will come apart quite nicely - I think the whole dash top comes off too.