It's time to replace it, but I did a search and cannot find any info on how to loosen the tensioner. I am sure there is a bolt that locks it, but I can't see it. I am hesitant to put a lot of pressure on it. It is an 01 F250 with a V10.

Any help?

 

No locking bolt, just a larger breaker bar is all that was needed!

 

yea most drivebelts use a spring loaded tensioner now...

 

1/2" breaker bar in the square hole. Push down.