I'm pretty sure the '05 already has a transponder. Turn your ignition on, without starting the car. Observe all the different lights that come on....seat belt, battery, oil, and so forth.
Somewhere in those lights, look for a little round red light about the size of a pencil eraser. If you have that light, you have a transponder.
All of those lights only come on for a few seconds, so for you to find the one you're looking for, you might need to turn the key off and back on a few times.
Also, how many keys do you have? One or two?
Transponder bypass options:
There are basically two types, one being cheaper than the other. The more expensive one does more things, and also requires only one key to program.
If you have two keys: PKUMUX, PKUCH2, or just an aftermarket Chrysler key (with the letter S stamped on the blade) in a universal bypass module. These units emulate a key; you need two original keys to program.
If you have only one key: I forget all the model numbers, but they connect directly to the car's data bus, and need only one key to program. They might also give you some extra outputs like tachometer and brake, saving a couple of connections to the car.
The Big 3 bypass module companies: www.xpresskit.com www.idatalink.com www.ifar.ca
Besides all that.....the 4113 is a reliable unit, with fairly decent instructions. (I think nearly all remote starters come with lousy instructions overall, but DEI products have the best instructions in the industry.)
It's good that you're mechanically inclined. The Liberty is exceptionally easy to take apart. The panel that's in front of the driver's knees drops down like a "door;" just pull on the top edge of it and you'll see what I mean.
You'll find taking the Liberty apart and putting it back together to be very, very easy. On your PC technician side, I'm not sure how much you work with testing and/or connecting wires, but that's the part you're probably going to have to practice a little bit......how to identify and test wires in the car, how to make solid connections to them.
Also observe that the steering linkage under the dash is exposed; you don't want your wires to get caught up in there. Pay attention to how the factory routed their wiring, and secure your new wiring to it with some zip ties. Before calling the job "done," be sure to move the steering wheel around, tilt the wheel up and down, operate the pedals, all while watching to make sure nothing is going to hang up and cause an accident.