hello, am looking for advice on replacing rear speakers on @`99 S80.

for example, what details will i need be concerned with as i plan on doing work myself? also, what speakers should i replace with to best match for quality sound? will i have trouble removing speakers (seem to have access from trunk)?

moreso, have HU-611; output 4x25w; impedance 40hm; voltage required 12v, negative ground.

other info copied from back of speakers to be replaced: volvo, 99w15, 8472374, 8ohm, 10347 sw*d* (sorry can't read my own handwriting on last 3 "letters").

in conclusion, should be an easy job (i told my woman), but when i approached local "sound systems" expert i felt he might not be considering my best interests and was just trying to make a sale. specfically he'd suggested either C2-600x or C2-650x by JL Audio for $170/pair.

last note: am not sure of speaker size, but volvo forum resource "seemed" to indicate rear speaker size= 6.5 with speaker depth= 4.

thanks in advance!

justjeff