Re: overland leather seats
No, you need to remove the existing leather to install them. The leather is installed via zippers and velcro and clips. I used to do auto upholstery its not hard but its time consuming. You need to know what your doing to install them or your screw it up pretty good.
I am going to watch this one closely.
I am 99% sure they will fit all years.
-Kyle '05 Dark Khaki (PJT) WK Limited 4.7L V8, '08 Overland Front End, Custom Exhaust, 245/70/17 GY Silent Armors, Bilstein 4600s, K40 Calibre DL Radar Detector/Laser Diffuser, CB.
Wife's Jeep: '06 Jeep Liberty KJ 4x4 2.8L CRD Diesel