Firstly, remove the nose pieces carefully if you are able to. Some nose pieces are removable with a screwdriver made for eyeglasses; it depends on the frame design. If you do remove the nose pieces, make sure you keep track of screws and any other associated parts. Secondly, Dust the nose pieces off with a clean, soft cloth to get rid of any excess dirt or grime. Thirdly,Put a bit of mild soap onto a wet, clean, soft-bristled toothbrush. Scrub the nose pieces with the toothbrush. Rinse them clean and dry them with a soft cloth. At last,Dip a cotton swab into rubbing alcohol. Run this over the nose pads to disinfect them. You can do this either while the glasses are still connected to the pads, or after you have removed them.