You do not have to take your interior apart!!!

I replaced mine by prying up the speaker grille inserts. (plastic piece with all the holes)

then you can take the two back screws out, but to get the front ones you have to cut off the tabs on the under side.. (when you reinstall your new speakers just put screws into the speaker frame unstead of the plastic clips)

it took me 20min total wiring included..

I have a 99' Civic EX