No problem. That website is awesome. So much useful information. Even though I have a YJ and the write ups relate to a TJ, there is still a ton of good stuff.
Or you could use a monkey wrench or pliers and loosen the housing that the oil cap screws into.
Taken from here:
http://www.stu-offroad.com/engine/oilchange/oilchange-3.htm
Local shop should have replacement oil caps.
Looking for Front Dana 30 axle and Rear Dana 35 axles. Must have at least 4.10 gearing.
If you have anything else besides the above with at least 4.10 gearing, please let me know. The only reason for the above is that the 4.10 gearing was stock on Jeep Wranglers from 88-95, 4 cylinder, manual...