How can I insert a belt around this tensioner that doesn’t have a pulley? It seems like I would have to break the belt or the outer frame of this tensioner to get the belt zigzagged with this tensioner and the pulley on the motor shaft.
Here are your parts
Replacement parts for WHIRLPOOL LEN2000LW0 | AppliancePartsPros.com
I would not bother, get rid of it and get an idler pulley/tensioner.
Those tensioners are just hard on belts.
As you can see in the parts, it is not even listed.
The drier floor should have the slots to take a pulley (Item 53 in Section1)