I recently replaced mine due to a leak in the tubing that wraps around from the front of the condenser past the radiator. When I bought my Jeep it had a 3" body lift (now removed) and when they put the radiator drop in, the metal strap for that rubbed a hole in the pipe.
Replacing the condenser isn't all that hard. If your leak is in the hard lines like mine was, you'll need the a/c disconnect tool to unhook the condenser lines from the lines going to the compressor and the receiver. I just cracked open my shop manual to get the exact procedure, here's what it says:
1. Disconnect and isolate the battery negative cable.
2. Recover the refrigerant from the system.
3. Remove the two retainers securing the upper condenser air seal to the grille panel and remove the air seal. (This is the plastic piece that's on top of the radiatior/condenser and has holes cut out for the hood latch.)
4. Remove the two screws securing the upper condenser mounting brackets to the grille panel.
5. Reach through the grille panel opening from the front of the vehicle to remove the two screws securing the condenser refrigerant tube and flange unit to the condenser. Install plugs in, or tape over, all of the open refrigerant fittings. (This tube and flange unit is on the left hand front side of the condenser as your looking through the grille opening.)
6. Remove the four retainers securing the lower condenser air seal to the frame rails and the grille panel and remove the air seal. (This is the plastic panel which runs underneath the radiator/condenser.)
7. Remove the two screws securing the lower condenser mounting bracket to the grille panel.
8. Remove the three screws on each side of the radiator securing the radiator mounting brackets to the grille panel.
9. Tilt the radiator and shroud unit back towards the engine using care to prevent the cooling fan blades from damaging the radiator.
10. Carefully lift the condenser out of the vehicle.
Reverse these instructions for installation of the new condenser. I'd recommend installing new o-rings on any and all lines you've disconnected. Make sure you use the green o-rings which are designed for air conditioning systems.
I bought my condenser off ebay for about $100.
Hope this helps.