You might check AutoZones web site for parts replacement details on this model.

I've never had to replace a tensioner & have a 4.0L, so I can't offer up any detailed removal/installation info.

If you bought the part from the likes of AutoZone, ect, may of them have a "loan-a-tool" program, that lets you borrow a job tool you might need, for a refundable deposit.

I'm thinking something like a electric wratcheting impact wrench, if you don't have shop air & air tool, for any stuck fast bolts you may run unto.

If you're going to be turning wrenches on this puppy, why not consider a repair manual or CD, it'll likely pay for itself the first time you use it, mine have over the years. Many like the detail of the CD, I prefer the portability of a book!!!!

Just some more thoughts.