Thanks for using Just Answer. I would be glad to assist you.
The stock belt tensioner uses a 13mm bolt to hold the pulley to the belt tensioner and a 15mm bolt to attach the belt tensioner to the vehicle.
Please let me know if there is anything else I can do to assist you.
Not a problem.
There is a tool designed for this, but you can use a 15mm wrench as well. All you need to do is put a 15mm wrench on the tensioner pulley bolt and turn it clockwise. Because of the tensioner design, turning the bolt clockwise will cause the pulley to move backwards and take the tension off of the belt. There is no need to touch the bolts that attach the tensioner assy. to the vehicle unless you need to replace the entire belt tensioner assy. as well.
I have included step by step instructions and a belt routing diagram below:
It should be pretty straight forward once you remove the coolant reservoir.
A serpentine belt tool makes it easier to do, but I have done several with a wrench. I prefer to use a socket and breaker bar because of the leverage aspect of it.
Just put the wrench on there and push. It should not take a ton of force unless you are using a short wrench. You should be able to ease the tensioner back and then remove the wrench.