Try opening the door on the other side. Using some sort of long tool, try closing the door that will not close by placing the tool into the other door you have just opened and pushing on the reluctant door. I just did that yesterday with a DL-109. I used a screwdriver, but a chopstick or a bamboo shishkabob skewer is less likely to scratch something.
If that does not work, then you can remove the shell.
