Hello and welcome to just answer Chrysler. Here is the procedure from the factory service manual for you. You will need to remove and reinstall the timing belt to do this.
Hope this information helps, and let me know if you need more assistance with this.
Timing Belt System
TIMING BELT TENSIONER
CAUTION: Index the tensioner in the vise the same way it is installed on the engine. This is to ensure proper pin orientation when tensioner is installed on the engine.
CAUTION: Keep the O-ring free of oil or grease.