JJ, it would depend on several factors, as to the route you should take to fix this issue. If your actual ground and power cables from the battery are still in good shape, as well as the ends of the cables, and your jeep is stock, and only sees mild off road use, you can purchase inserts that go inside the cable ends to help them fit tighter on the battery posts. These are usualy found at places like auto parts stores, or sometimes even walmart in the battery and electrical section.
If the cables are still good, but the ends are the only issue, you can also get inexpensive replacement battery ends, and all you do with those is cut off the old ends, strip the wire back about a half inch, slide the wire in between the two halves, and bolt them down. There are several different types of replacement battery terminals, some are inexpensive, and easy to use, and some are a bit more money, but tend to last longer and hold up much better.
If the cables are bad as well, there are several routes you can take. You can usually purchase replacement cables through most local parts stores. If that option is unavailable to you, another option is to measure the length of your existing cables, and see if your local parts store has pre-made cables that have the round ends on each end, and get replacement battery ends, and replace them that way.
When I go this route, what I usually do is get the new cables, get marine style replacement battery terminals, and replace the wing nuts on the replacement terminals with the nuts that have the nylon inserts in them, that way they don't vibrate loose.
My favorite way to replace the battery terminals, though, is with positive attachment battery ends. These ends are simple to use, easy to connect, and give options for multiple wires, for things such as starter, lights, and other assorted accesories, plus they have different size holes in them to attach different size and gauge wires to. The way you attach the wires is to strip back about a half inch of wire, slide the wire into the end, and then use an allen wrench or torx bit, depending on the style of the end, and tighten a set screw to positively lock the wires in place. And, for severe use, if you strip the wire back a bit, and then solder the end of the wire, then insert it into the terminal, and tighten the set screw, they rarely ever come loose, no matter how rough you are on the vehicle.
One of the best places to get wiring from is Painless Performance. They sell everything form single sections of heavy gauge wiring to entire wiring harnesses, for everything from classic, to custom, to off road, to boats, and everything in between! They are the single best source I have found for wiring, from ignition wiring, to wiring harnesses, to custom stereo wiring, for almost any vehicle on the planet.
The images i added show several different types of replacement battery terminals, from standard inexpensive ones, to some of the different available more durable styles.