Zero Turn Mowers

I have a RZ4623 mower that is 2 weeks old. Today it dug a blade deeply into the dirt and then once cleared the mower belt idler is now loose. If I could get instructions on how to restore tension to it I could fix it. Can I get the technical mechanical fix instructions for this problem on the mower and a manual for said instructions. Everything is clear no belt obstructions etc. Nothing else is wrong except the tension issue.