Serpentine Belt keeps coming off after starting on 3.5 V6

To update the repair, I have new belt tensioner and in the process in installing it, this is to find out what is causing a winding noise, along with fixing the up/down engine idling,. So far the top tensioner bolt is removed. Now the lower bolt is next.

I have the lower /front splash pan removed for access but,still looks hard to get access with a tool, without removing more clips to the fender well. I am looking for away to get to the lower bolt of the tensioner without, removing a tire, clips, jacking the car up etc... Waiting on a stethoscope to check tensioner and power steering pump for noise. I have no mechanics rolling creeper however, access to a full roll away tool box, to use. Any help on this repair would be much appreciated.