Uhhhh...
I can't.
I can't because of the risk of losing my game files. If I launch GM2, a message will appear saying I need to remove the old engine, but if I remove the old GM engine, I might just lose my game files.
i think you can easily port the old gamemaker files into gms2
okay MAYBE i will remake the game into gms2 MAYBE i will make it a FULL experience rather than 4 buggy parts