How can i open my lava lamb to change the bulb?

i cant open it, its i tihnk screwed in the black part, but i dont wanna force it to unscrew and ten it will break, heres a pc of mine..



http://s26.photobucket.com/albums/c105/greekman102/?action=view%26amp;current=DSCN1340.jpg



http://s26.photobucket.com/albums/c105/greekman102/?action=view%26amp;current=DSCN1339.jpgHow can i open my lava lamb to change the bulb?
The bulb has to be in the base. The enclosed glass part of the unit is separate, and sits over the bulb and base assembly. Look for screws or any other obvious entry method to get the base open, probably the bottom.