Your rebuild kit should include all of the main bearings as well as the needle bearings, so remember to swap in the new components as you go. As you (carefully) pull the main shaft assembly apart, you will notice three (3) ball bearings in the mix. Don't lose these. Also, don't try to remove a component if there is a ball holding the component in place. Carefully remove the ball and place it in the assembly order. Once the shaft has been disassembled, go back through the parts you have removed and make sure you replace all of the bearings with new components that look identical. Then reassemble the shaft in the reverse order that you took it apart. This is where keeping everything in order makes the difference. For a reminder of the order, take a look at this. The main bearings will need to be pressed back into place, so be careful not to lose track of the ball bearings shown above.