assuming its just a tear down at the knee and there's still a at least a little bit of tissue still connecting alot depends on how long ago you did it and how your body feels/response
ice for the first few days to a week
then i go to warmer compressions, massaging (might not do too much but feels good), and start stretching it / going through lower leg rom very cautiously (dont do stupid shit like aggressively flex/extend, etc. you should know how instinctively far you should push your stretches)
slow cycle work to get rom back again and you can start to do (slowly building up) exercises to get strength back in it (if you give a shit about that stuff)
of course take advil/nurofen (ibuprofen) if you want to. no need to go nuts on it though for a hammie. dont bother going to a doc or physio.
in worst case could take up to 5 weeks or so. just use common sense and dont do stupid shit (aggressive movements or jump straight into weights without Very slowly bulding up)
keep us updated if it turns a kickass shade of purple