Locked out of trunk

Electrical problem 150k miles

Hi guys, The battery on my C230 is DEAD! I can't access the trunk with the emergency key due to the fact that something is jammed into the key hole - can't tell what is is- but it's preventing me from accessing the trunk where, of course, the battery is located. How do I -1), charge the battery from under the hood, or 2), break into the trunk without screwing-up the locking mechanism too badly? I have already had AAA out to try to get in but to no avail. (They may have been the ones that jacked-up the lock). Anyway, any ideas gentlemen? I really appreciate it.