Just got done replacing all speakers and just that alone was a chore. You almost have to remove the better part of the dash, unscrew the passenger airbag module, and it is not the most fun to do. However it can be done.I have the 8.4" Alpine system in my Jeep. It's kind of funny that the Dash speakers are 3.5" but as far as aftermarket speakers Alpine only makes a 3" component speaker and a 4" coaxial.
Also.... to all you audiophile experts.... I was thinking about replacing all my speakers to larger ones by using the metra kit for the kick panel and the ssv adapters for the sound bar. I was thinking of staying with Alpine speakers because I've always been partial to Alpine. I wasn't on planning on adding any additional amplification just wanted a slightly larger speaker. What Alpine series would be closest to the factory Alpine speakers? E, S or R. And one last additional question... Are the existing speakers coaxial or component? Didn't want to buy Coaxial and not be able to mount the tweeter.