One of the belt rollers should have a nut on the front of it. When you turn this nut, the entire roller moves with it. It takes a good amount of force, since the roller has a tensioner spring to get rid of slack in the belt.
You should have a friend help out with this. Youll have to hold the roller back while the other person puts the belt on, and have them hold it in the correct position before you can release the roller.
I recomend to not use a ratchet because it will almost certainly break the ratcheting mechanism.
Go and pick up a cheap breaker bar and use that. You can also get a piece of steel pipe for a couple bucks and put stick it on the end of the breaker bar to get more leverage.
