7mm socket on the bleeder valve, slowly open till it bubbles, once it starts to leak out without bubbling, close it off... wait a bit, run engine, press on the gas getting it up to about 2500rpm, open valve, if no air comes out you're done for now...

myself when i had to do this it took bleeding the system several times over days. id bleed it one day
next morning while cold, pop the rad, fill it up, bleed, bleed, wait a day, bleed lol

maybe not the right way, but i fixed it.