To unlock a door that has been locked from the inside, look to see if there's a tiny hole in the knob, if ther is you are in luck. Take a hairpin and push it around in there till it pops. It'll open nicely. If no hole you'll have to try taking the hinges off if there the ones with a bolt that pops right up. Good luck, if this doesn't work you can start unscrewing any screws and see where it takes you.