"Go get an angle grinder and a coarse sand paper grinding disc of some sort"
If you do this you will seriously regret it when it comes time to fair the surface. A random orbit disc sander with a relatively coarse grit (60, perhaps) would be a much, much better choice. I've done it both ways; I should know.
Either way you are in for some work. Have fun. Oh, and if you do end up sanding with a disc sander, change out disks often as the lose their abitility to work effectively fairly quickly and they are much cheaper than your time (I hope).
Cape Dory 28 "Dulcinea"