Belt tensioner

Was not aware that the nut on the belt tensioner releases the tension to install the belt, was doing it the old fashioned way, with a crowbar, anyway, broke the black plastic wheel, is this replacable? Or do I have to replace the whole belt tensioner?

Oh No! You Made A Boo Boo! Its Not That Bad But You Didnt Say Which Engine It Was. Most Of Them Are Available Aftermarket At Auto Parts Stores If Not Go To The Junkyard And Get One Cheap

It's a 3.8 V6, K engine, no turbo, I fixed it, $10 for the pulley at Autozone, one of the easiest things I've done, once I realized the rtainer bolt is reverse threaded.