It should just mount up. My sound bar had 5-1/4's in it and I just put Alpine 6-1/2's in it. No cutting.... Just mounted right up.
98' TJ Flame Red, OME lift, custom bumpers, Warn M8000, 33/12.5/15 GY DuraTracs, Cepek DC2 wheels, Richmond Powertrax, SB flat fenders and rear flares.
10' JKU Mango Tango, TF performance leveling kit, 33/12.5/15 GY DuraTracs, Mamba M13 wheels.