Scotts L1742 Pulley Help

I'm very uneducated with lawn mowers so I'll try to explain this as best as I can. I'm pretty sure this an idler pulley. The pulley has been wobbling so I took it off to replace it and it turns out that the screw that holds it in place was stripped and turning freely while the pulley was turning. I was trying to remove the screw to replace it but the screw is flat on the bottom and you cant use a wrench. But on top the screw has this round piece that fits in the pulley for the pulley to rotate around. The round piece is bigger than the hole so I can't just knock the screw out and the round piece is made into the screw so that doesn't come off seperate. I'm not sure how the manufacturer assembled this since it's made into the hole like that but I was wondering if I should just cut it out and if I do what would I buy to replace it since this screw would be cut out and I can't put another like it in? I hope you can understand what I mean. Thanks