To clean brass hardware you will need and white light duty scrubbing sponge, rubbing alcohol,clean soft rag and possibly a scouring low abrasion cream. First you would need to put some rubbing alcohol on the sponge side and gently agitate it with the grain of the brass. If it is a tough stain you would need to then apply you cream and do the same. When done take a clean clothe and wipe clean. You would then use a yellow treated dust clothe to buff it out.