belt broke maytag

HI,

My washer stopped spinning, but all else seems to be working. When I took off the front panel, I found a broken belt laying on bottom of washer. Also, there was a round plastic black piece also just laying there. It is approx 6 inches in diameter with a spoke design.

What is that piece and where does it go? What do I remove to get the best access to belt area. What do I need to know to replace belt and get the tension correct since I can’t go by what the old belt was tightened to.

thanks, teressa