Ok I don't have much confidence in my ability as a DIY guy but I don't want to pay inordinate amounts of cash for a 'professional' install. Where (how) do I get the door trims off? Is there a certain spot where I can pop out a section and follow on? What about the dash? Ok I'm starting stick out as a n00b now so I'll ask if anybody has a link to a site which tells me how to safely do these things without killing my interior

 

If you work on the door panels first make sure all the screws are out then start in the bottom corner (either one) and slow and carefull pull on the panel eventually you will get it to start to POP off just be carefull not to break the panel where the clips are attached. Get new clips from your local stereo shop before assembly to insure everything stays back to gether tightly.
As for the dash all are a little different but use the same steps as you did for the panels.

Like I said earlier just take your time and dont try and force anything (although it will take a little muscle sometimes it requires more finess).

Good Luck

 

there is like 3 to 4 screws and then just pop it off.