You can do it but it takes a large amount of time and patience by marking the heavy spot with a fine point pin and even when you get it where you think its perfect it still might be just a tick out, you would just have to run it and see, as long as its not to far out, it won't hurt anything. I would suggest to send it to Carlos at RTI unless you have time to do it yourself.

I would think that if you were using bearings to balance it that you should use the current engine bearings and not the new ones unless your current bearings are extremly wore, all experiences I have had with new vs. used bearings is that the used tend to be more free because of the wear and lubrication.