To remove vinyl glue, first you have to strip the glue and the paper that stick on your concrete floor. Then put a drop of xylene in a piece of cloth. Then scour it, If the the glue is still there, use a tri Sodium phospate or they call it TSP, use this powder with water. Then pour a little bit of your TSP solution to your floor. Then use a floor buffering machine use a coarse black pad in buffering your floor. Believe me, that's how I took out mine when I stain my concrete floor.