P.M.
Lay a bag of ice over it to freeze it, and chip out as much as you can. A non-toxic solvent like Citra-Solve may take out the remainder. If it doesn't, you might want to carefully snip out some fibers, and glue in others removed from under the couch or inside a closet. It may always feel a little funny underfoot, but should be pretty-near invisible to the eye.