if oyu can pull the back seat out, get a socket on a long extension bar and unso the the striker or a long phillips head and undo the 2 latch retaining screws
if that fails
Try removing a speaker from the parcel shelf and doing the same
if that fails
grab the boot lid either side of the boot lock and pull really hard and force it open, it will break the diecast lcatch but you can replace it, put a VK/VL one in with a electric solenoid. You can fit a trigger cable to it on the inside of the car somewhere hidden if you dont want the electric button for emergency use.
If that fails you didnt pull hard enough, try getting someone who doesnt care about your car to pull on it
it has to be really hard.
Else
Try drilling out the lock, make a decisionweather to hack a taillight to pieces or the boot lid, but i have always been able to get into a boot using the above methods. make sure you get a replacement tail light before you hack at one
Else jam a flat blade screw driver int he lock and slot and give it a really good twist, it will bend the toungues off the boot lid and should open the boot.
cheers
Scott