oki guys... i finally got my 5 series back from the mechanics, there were a few problems with it and alot of money

but the car runs better then it ever did before...
anyway
does anybody on here who owns a 5 series atleast a 528i think the speakers are shit? i do, not enough bass and im wanting to put some subwoofers inn, BUT i dont want to change the look of the inside which means i dont want to get another new cd player/headunit, my question is does anybody on here know how to take the cd player/headunit out, because im worried, that if i do it i might scratch or break somethin, so are there any pointers or tips or something on how to take it out.
thanks in advance
eddy