Other than needing a few specialized tools, it is an easy fix. If you decide to open it up, replace the bearings (do not reuse them, they are cheap) and the grease as well. If you see significant wear on the spindle or the cups, time to look at a cartridge replacement. BB choices depend on the crank. And if you have an old cottered crank, this would be a good time to upgrade.

Find a shop you trust, or a good co op. Seems like Minneapolis has some good co-ops, so that is where I would start.