Sorry about the inconvenience. Be sure you've cleared out any extra material from the holes that was left over from the printing process. If that doesn't work, if you have a sharp knife, try shaving down the inner walls of the hole. After that, try working them on with a wiggling motion and tap them against a table top to work them on. You should be able to get them to wedge on with friction, so you don't need to use any glue. If none of that works, let me know.