Yep, what LeeAnn, HJ, and Luke said.
No need to even jack it up. The bottom nut is a 15mm (the bolt is a flag bolt so the tab welded to the bolt prevents it from spinning), while the top bolt is 15mm and the nut is 18mm. Turning the wheel will give you plenty of room though I don't even do that to get to the bolts/nuts.
Word of advice: Use OEM sway bar links ONLY! The stuff from AutoZone, Pep Boys, Advance Auto, etc. is poor quality and won't solve the clunking noises. I thought there was no difference between the cheap stuff and factory till I nearly went crazy from the clunks even though I tightened the bleeping things multiple times. (HJ, remember me crawling under the Jeep at Windrock trying to tighten down the stupid things? I was getting bug-eyed even then and finally lost it while at TomMudd's house after installing the new front and rear diffs :boxed
Finally I just bought Mopar links from one of the online Chrysler parts depots and problem solved.
Lesson learned :manos:
Bob