- And got the T-shirt
If it's a scab, just leave it unless it's oozing pus, or there's a lump underneath it. You really shouldn't bother a scab unless something is happening underneath -- it's the body's way of healing a wound.
But if there's a lump, or active infection, then get him to a vet. If the scab comes off (without your picking at it), then you can apply a tiny dab of triple antibiotic ointment with a q-tip, and rub it in well. But if there's an abscess underneath, that won't really help anything, and it may require lancing by a vet.