Diy
I seem to remember it was right hand, you will know right away, the nut is not torqued that tight, it is threaded into an aluminum housing.
I toyed with the idea of various high tech bearings, like Ceramics, but stayed with OEM quality. They are not expensive and in the future: when you hear more noise than usual, just replace them, do not wait for them to scream or vibrate. You could end up having to replace more than the bearings if you wait too long.
Oh, you will need a small male "torx" wrench to remove the brushes. I think you should have enough info to handle this job.
I think the bearing numbers are:
608 , and 6002 . I used double sealed bearings, they can be had in various shield or open styles. I think OEM was double metal shields, though I used double neoprene on mine. That shielding will be a two letter code after the number I gave you. Like: ZZ for double metal, RS for rubber seals, I used 608RS for the rear bearing, and 6002RS for the tool side(front) bearing. They work great for me.
PM me if I can help further ... Lou.