These guys may seem harsh, but we're just trying to communicate to you that if you want to avoid destroying your Jeep through neglect, you will want to get on top of maintenance NOW. If you don't have time, take it to a Mr. Lube. They'll do it while you nap in the driver's seat for 30 minutes. They'll change out engine oil, diff fluid, transfer case, and tranny fluid.
Or don't....it's your Jeep, after all.