It's much easier to mount the speaker if the radio is removed, especially if it is the original "Kleenex Box" sized radio.
Other than that it's pretty straight forward.
I purchased one of those newer speakers that has two smaller speakers from Harrison Classic Car Audio
http://kenharrisonradios.com/new_page_4.htm that fits in the stock location.. I wasn't happy with the sound quality and eventually ended up going with a couple bookshelf style speakers under the seat.
