Though there wasn't info on actually swapping them out. So I am going to do a walk through.
Step 1: Printing Parts
Step 2: Removing The Y Carriage
Step 3: Installing Motor Mount
Step 4: Belt Holders
Step 5: Installing The Bearings And Gear.
Step 6: Installing The Belt.
Step 7: Final Thoughts.
This was all done at the tech shop in SF and you can visit their website at TechShop.ws