If the light is solid green it means the PE isn't really hibernating even though it says it is. When it is hibernating the power light should flash. Have you tried pressing every button on the tablet to see if there is any response?
The only other options I can think of is to let the battery lose its charge and die off and see if it will power back up (BEST OPTION)
or if you are handy with a screwdriver you can lift the bumpers on the tablet side and take the back off and unplug the battery (NOT RECOMMENDED). I am NOT recommending this if you feel you cannot do it, but I can't judge the level of your abilities. I put the disclaimer in because I don't want to be flame sprayed by other forum members for even suggesting such a thing. However, I know that some are capable of it. I hope everything turns out OK.
Here are pictures of the PE internals taken by a PE owner who opened up the PE, if you are inclined: