This is a simple step by step to install a 38 inch mower deck on a MTD Yard Machines lawn tractor. I had to convert my lawn tractor from snow plow to lawn tractor. You can use these instructions if you need to service the drive belt or any pulleys or mower cutting blades. If you have a loose belt this info might help (regarding the spring installation)

Missing springs video link at end of this video if you need help with locations