kpd1031

The tensioner is spring loaded. You don't remove it. There is a 1/2 inch drive hole in the tensioner that you put your 1/2 inch ratchet in, and push the tensioner in the direction that relieves the pressure off the belt so you can remove the belt.

157dB

Maybe he is not up to it with all
the questions.
Maybe its stealership time for him?
Serpentine belt replacement is one
of the simplest things to do...
Just slightly tougher than opening the door,
getting in, turning the key, pressing the pedals
and spinning the big wheel in front of you.

tx_zstang

Use a 1/2" drive extension on a wratchet or breaker bar, put the square end in the tensioner, and push down to loosen the belt.
If your belt has that many miles, get a replacement as a spare at least. And learn how to replace it and write down how the belt loops around everything, while it's in place. If it breaks and you have no idea on how it routes around everything, well, that wont help you much.

I have a practically-new Ford Motorcraft belt for the 4.6L, has about 500 miles of use on it; bought it new form Ford earlier this year; will sell for $20 shipped.