rbw

My radio on my 93 convert stopped working after local dealer left it in rain. In my search to fix the problem I am hearing about multiple fuse boxes, I know of one under the hood by battery although I dont know how to open it yet and the one on the end of passenger side dash board. I saw something online leading me to think there may be another fuse box under passenger side front floor. Is this true, if so how hard is it to open? Also my bose radio receiver (CDM box) model number 16178351 got wet. Can I replace it with other model numbers, if so what other model numbers can I use? any advise on going to an after market unit like Kenwood or Pioneer ?