It isn't necessary to remove the side plate for normal cleaning. Depending on use and accumulation of dust-dirt-lint, it may never be necessary to remove it. As for lube, I spray a short burst of my favorite PTFE lube into the frame, ahead of the cocked hammer, about every tenth cleaning. The carrier washes down through the action and when it evaporates, leaves a very durable, slick film that keeps the works smooth and clean.
If you feel called to remove the side plate anyway, get a copy of Jerry Kuhnhausen's S&W shop manual for revolvers. His method of plate removal leaves little chance of messing up the very fine join line, and leaving an unsightly "ridge".