The "brass piece" is not inside the plinth, which you seem to think. It is the flat, round plate that is screwed into the plinth that surrounds the pulley. It is on top of the plinth, and is fixed by four hex socket screws. "Below the brass piece" simply means applying oil at the bottom of the pulley shaft, which spatially is below the brass plate/piece (think "inside" the brass piece). The problem is, of course, that the space between the brass piece and the pulley is so narrow it's virtually impossible to apply oil without getting some of it on the brass. You definitely do not want to get any oil on the plastic part of the pulley for obvious reasons. That's why I recommend using a needle.
Hopefully, your motor noise will disappear after the lube job. Mine didn't. It's possible that I applied too much oil, but Mike acknowledged that dirt, dust, and drying oil is likely to cause low level noise in the pulley. Let us know how it goes.
Hopefully, your motor noise will disappear after the lube job. Mine didn't. It's possible that I applied too much oil, but Mike acknowledged that dirt, dust, and drying oil is likely to cause low level noise in the pulley. Let us know how it goes.