How big of an area is it? Is the area small like somthing it hit somthing when it fell? Get a large screwdriver and place some rags around the tip, tap in in with a small hammer, the rags should keep the aluminum mast from gouging when the screwdriver forces its way into the track. If there is a larger area you might have to do this with several screwdrivers. If this scares you you might try making some hardwood "wedges / shims" and drive these in. There is not very much room to work inside the sailtrack to make this work. Go slowly.

Sorry about that reply, take two putty knives, 1 layer of cloth for each knife, and place middle of knives at the pinch point, now slowly drive the screwdriver in between the knives at the pinch point. Presto chango your track is fixed, Still - go slow you don't want to open it too wide.