Use a paper clip
You should look at the center of the doorknob and see if you can see a small hole at the center of the knob. If there is a hole you should find a paper clip and create a straight stick out of it.
You should then push the paper straight into the center of the hole while turning the knob. You should continue feeling around until you hit the lock button. When you find it you should push it with steady pressure. When you do this, the clip will push in the release mechanism thus unlocking the door.
Use a thin screwdriver
If your knob looks as if it requires a key you should slip the head of a thin screwdriver into it. You should then turn the screwdriver on the left in order to unlock the door mechanism.
Make use of your credit card
Here you should slip your credit card in between the door and the door frame then slowly slide the card downwards while at the same time pushing it further from the crack.
When you reach the level of the handle you should work the card into the crack and use the card to push in the metal bolt that keeps the door closed. When you push the bolt you will open the door.
Remove the door knob
If there are no openings in the knob you should consider removing the door knob. You should remove the screws with a screwdriver and remove the knob.
After removing the knob you should reach into the hole in the door and remove the bolt that connects the knob to the hole in the strike plat. After opening the door you should replace the knob pieces the same way that you removed them.
These are some of the ways in which you can unlock a bedroom door. For ideal results you should follow the instructions to the latter. While you can easily open the door by yourself, its good that you hire the services of a professional locksmith to do the work for you.
The professional will not only do the work perfectly, but he will also ensure that your door is secure.