hi i have a 2002 gt with mach 460 i wanna replace it, i have some ?'s like can i replace the 5x7's that might noe be exact but close, with like aftermarket subs without changing the wiring, i also have a pioneer mp3 player with rca outs i wanna put in i have no idea on how to replace this stuff, is there a way to replace the tweeters too ?