Massage it out as much as you can, nurse or pump, apply heat and can alternate with ice
Nursing can help a lot too. pump, take a hot shower (massage while you're in there) then nurse you can massage then too
both of my arm pits were clogged golf ball sizes... I took HOT showers and massaged, instead of warm cloth, I used water bottles, they stayed hot for hours, I elevated my arms when I slept, I pumped every 3 hours, while massaging at the same time. they went down withen a week. :)
I read somewhere that someone had to nurse while on all fours so gravity would help, I don't know how true that is but it can't hurt to try!