This past Monday the pulley on the tensioner (for the accessory system) seized up. I have a replacement pulley, but my question is - how do I get the old pulley off. The tensioner has a 15mm nut that is used to rotate the tensioner to install or remove the serpentine belt. If I turn that nut with enough force, will it come off so I may remove the pulley?

Thanks in advance for any advice!