The micro scratches may be used as an auxiliary indicator of a matched pairs' preferred position, if the front slinger is obscuring one of the faces (this can be an issue on the older TL, and possibly also the TM/UM).
Carefully dress down with a hard stone, only if necessary.
Use latex-free gloves, more particularly the purple polymer gloves which come talc-free.
These are intended for surgeons/technicians who are allergic to latex.
Most larger drug stores should have them. Also some industrial supply stores.
Wear a Tyvec® cap on one's hair.
A Tyvec "gown" would be good, too.
If someone jokes that you've become a cross-dresser, tell them to go to Hardinge Hell (somewhere in the Eastern hemisphere).
At the risk of appearing anal-rententive, I'm primarily concerned with the older oil-lubricated bearings, which are open (that is, unshielded) and have phenolic or brass cages, not the newer bearings which are shielded.
I am advised that these unshielded bearings come pre-coated with a protective lubrication which prevents oxidation, that this coating is compatible with the recommended lubricant, and should not be flushed with Bra-Kleen, or any other solvent prior to installation.
Donie's observation that the spacer is a precision device is significant. It is carefully honed to its final dimension (length) and it sets the bearings' preload. Never use this component as a "tool".
Make a set of removal/installation extractors/drivers, perhaps actuated by a length of 3/4" all-thread rod.
Banish all "dead blow", lead or brass "persuaders" from your workplace while working on the spindle bearings.
Go slow, take rest breaks, make no mistakes. You only get one chance to get it right and to still maintain the 40 millionths tolerance these machines are capable of.