wash your hands and the blister with warm water and soap.
swab the blister with rubbing alcohol.
sterilize a clean sharp needle by wiping it with rubbing alcohol.
use the needle to puncture the blister. Aim for several spots near the blisters edge. Let the fluid drain but leave the overlying skin in place.
apply a antibiotic ointment to the blister and cover with a bandage.
use tweezers and scissors sterilize with rubbing alcohol to cut away all the dead skin after several days. Apply more ointment.