Help! - accessing the battery to charge it when the boot won't open...

[tintin]

The title says it all really...my beloved D2 S8 has been sat on the drive for a wee bit too long (probably about three weeks, but it may be a bit longer). So my first task this morning was to put in on a trickle charge...

Unfortunately, it seems that the battery is so flat that I can't access the boot: the remote won't unlock the car, but I can unlock the drivers door manually with the key. Then I can't open the boot with the driver side door button, or the key manually in the boot lock - it will turn in the barrel, but doesn't do anything...

Any ideas, anyone?