Not much really given the movie was only 103 minutes or barely over an hour and a half. So they could fit that into a two part episode pretty easy. The average TNG episode is about 45 minutes minus commercials so, they'd only have to cut 10 minutes. Cutting Data out at the beginning and the alien reception would pretty much do the trick.
It probably would have stood up better as an episode. The Baku still hard to be sympathetic with, but a below par two parter wouldn't be as disappointing as a below par movie. I still look on a two parter like Birthright with a small amount of fondness afterall.