I ran into this same problem. What I did was...I got a couple of small allen wrenches, pushed down on the hinges, inserted the allen wrenches into the holes. The allen wrenches secure the hinges in place while you position the hinges back onto the keepers. Once you have the hinges on the keepers securely, lay the door down into the wide open position, pull out the wrenches and voila door is secured.
As Priscilla said you can also use nails, but thick ones are recommended as those hinges are pretty strong.
What I would suggest is if you plan on taking your oven door off, put something in the holes before you take the hinges off the keepers. I just jerked the door off and found myself in a predicament. lol!
Good luck. ;-)
Stephen Orrick, June 2007