Easy to release the boot from the inside if it's locked - there's a small white square behind a piece of translucent plastic with a slit in it. Put a screwdriver through the slit and slide the white bit of plastic to the left and it'll pop open. Hardly takes any force at all!
Just fixed mine this weekend, on mine the mechanism itself was fine but the contacts within the boot switch had corroded and weren't making contact properly anymore. 5 mins with a bit of sandpaper and some copper slip and it all works perfectly now