trunk is stuck shut

It sounds like the trunk release motor isn't functioning. If so, the only way to open the trunk and replace the release it is to remove the rear seat(or fold them down if optioned). Once the seat is out of the way crawl into the trunk and use the manual trunk release to open it.

If it is due to a flat battery? You can access a power connector under the rear passenger floor carpet to charge the battery and open via the key fob.