So my YJ vent window locks no longer worked. The locking portion of the handle was just worn out. When I first looked it seemed as the only way to "fix" this was to replace the entire vent window assemblies. As it turns out there are replacements for the YJ vent window locks. LatchWell is still making kits for vent window locks.
Here are the LatchWell compatible part numbers. They are for a 80-91 E Series Van. They were almost an exact match for my OEM handles.
As for replacement you will need a very small punch. As the roll pin is slightly smaller than 1/8". It measures 0.10" roughly. Knock this out from the top. Support the lock, and be careful. You are beating on something attached to glass. It should take much and once the pin has started you can pull it out the bottom with pliers. Have the window open, turn the lock, you can do what ever makes it easiest to get to.
Once the roll pin is out, the lock will just pull off. There is a coil spring in the center. This will be replaced with a new one from the kit. The spring washer against the window needs to be saved. Make sure you clean everything up before re-assemebly.
Below is the replacement lock kit. As mentioned it doesn't have the spring washer, you'll have to re-use that. The only real difference is it doesn't have the checker pattern on the handle.
Start the new roll pin the handle before you put on the door. Trust me it will make things much easier. Just start it though. Otherwise it will prevent you from putting the handle on and you will have to knock it back out some. Other than that it's just a matter of pushing the handle on, and knocking the roll pin back in.