i had this problem when i sold fur coats.
i'd lay my pant flat. and with a damp hand, rub my hands down the legs of the pant leg.
sooo much fur came off. i'd do t about 10-15 times on each leg. Every time i'd wear the pants. Once in awhile, maybe every other week, i'd take all my wool pants to get dry cleaned. the would come back fur free