Yes, those are the drain and fill plugs.
Be sure you can get the fill plug open before opening the drain plug.
Not sure if the '99 xj has a torx or allen plugs.
'93 Cherokee Sport 4.0 man. 4.5" Black Diamond/ O.M.E., JKS control arms, discos, track bar, rear D44/detroit, 35x12.5 BFGmt's,33x13.5 LTBs,AlloyUSA shafts, oba, Warn M8000 multi-mount
'97 Cherokee Sport 5spd,231, white, stock
'90 Cherokee Pioneer 4.0 auto, 6" homebrew long arm lift, 33x10.5 BFG MT's, etc.
'87 XJ 2" lift
'96 XJ stock
"Personally, I've learned so much from my mistakes, I'm thinking of making some more."
"Don't believe everything you think..."