Ahhh...Mopars wonderful "Ratchet-tight" oil cap....
2 Solutions..... 1) Get an old serpnetine belt and a pair of pliers. loop the belt around the cap , and grasp it with the pliers as close to the cap as possible....Sorta looks like an Oil filter wrench now, doesnt it....Turn it off....
2) pry the top off of the cap, ...you will find a small Spring. remove the spring and set it aside.....Take two flat blade screwdrivers, one into the cap hole, the other at a 90 degree angle to the first, and pry on the Teeth of the cap.....If this makes no sense, it will once you see it... once the cap is removed ,reassemble it, and put a finger full of oil on the seal....And reinstall...Just not so darn tight this time