I am sure that someone has already done this but maybe this will also help someone that wants to put the round tail lights on their YJ.
So I decided today to go ahead and swap my tail lights out because I was bored. Here are photos and step by step process I went through. If I missed anything I apologize up front and feel free to add anything to the post. I am also sure this will work on others but will be tomorow when I do it on a TJ.
First off here is a product list I used
2 tail light assemblies from walmart for 16$ each
4 1/2" metal hole saw from lowes $35
butt connectors from walmart $4
I also needed these tools.
-Phillips head screw driver to remove the old lights
-3/8 socket and small extension to remove the whole old assembly
-drill for hole saw. little battery ones will not run this big of a drill bit.
-Voltmeter or test light for checking wires
Removed the old lights by taking the four phillips screws off that hold the lenses on. After that there are 3 3/8" bolts that need to come out. You may also need to disconnect the wire harness from each light before you remove them. My harness was long enough to come out of the hole after removal.
is to mark where you want to cut the holes. This is where it can vary a little bit but also be careful when drilling. You don't want to cut to high or cut any wires. I measured my center mark from the screw holes and than made sure that i would not cut into the gas filler and also not to go to high because you can cut into the cab if not careful.
Here is a pic of how i measured. Sorry its already cut and not on the jeep
Now mark the other side the same as the drivers side.
Your now ready to cut your hole. First you need to use a center punch so that the drill does not want to walk. This is where you must be careful. This is a big hole saw and once through it will want to catch and twist the drill. You will also want to clean the edges after drililng and put some paint on so not to rust. Once you get through all the way it should look something like this
Wiring the lights. Ok, so now we have our hole so we need to wire. You can do it two ways. Either use the stock connectors and cut them or just cut the harness on the jeep itself. This is user preference. I cut the wires on the harness and just spliced into them. I used butt connectors but will probably go back and solder them using shrink wrap. The way you check which wire needs to be where is by using the test light. Turn only one thing on at a time and connect the matching wire on the light harness to them. The passenger side does not have a ground so you can just splice into the 3rd brake light ground. If you need more on wiring just pm me or message on here. It can get as technical as you like.
Go ahead and install your grommet and then plug the harness into the light. Than you will just simply push in the light into the grommet. It will seat nicely unless you push it all the way through. If that happens just start over by unplugging the harness.
is to test the lights and make sure all turn, brake and tail lights work.
Now your probably asking about reverse lights and tag lights. Yes I know you must have them so my solution later to come is led tag bracket lights spliced into the tail light harness and using the left over reverse wire and running two spot lights on the rear of my trailer hitch. This will also be on a switch so that when im doing some night offroading and have to pull or be pulled i will be able to light up behind me.
Also, this is how i solved the issue of overlaying on the filler area.