Soak in a warm epsom salt bath for 15-20 or so, then what I do is use my nails and tweezers/exacto knife (disinfected with alcohol or boiling water) to start prying off the scab. Any cheese-like substance underneath also needs to get pried out, that's the infection.
Once I get it as cleaned out as I can, I use Vetricyn spray to clean up the area, and put some Neosporin in the wound. Get some vetwrap, cut it in narrow enough strips to easily work with, and wrap up the foot (not to tight, but tight enough to stay on).
Redo the soaking the next day, clean out the wound again if needed, more Vetricyn/Neosporin if needed, wrap it back up, and repeat daily until the wound starts shrinking and is no longer so swollen. I treat for maybe a week, then give it some time for it to heal up as much as possible, then re-treat if it's a stubborn case but by that point the scab is usually greatly reduced in size.
Many people do isolate birds that are being treated however I let mine rejoin the flock as I don't want to reintegrate and honestly they do fine with bumblefoot treatment as long as the wound isn't too extreme. If weather/run is wet/muddy then keeping her inside or in the garage might be a better idea, however I've always planned my bumblefoot treatment around the weather so birds stay outside.