There's no need to move it or use electricity to defrost it. You can simply turn it off and open the door. Be prepared for it to drip, and catch all the water once it starts. After some time, you'll be able to remove large pieces of ice by hand (or a plastic tool). This is a great time to wash the inside. Be sure it's reasonably dry before you turn it on again.

And make sure the seal is good, or you'll be doing this every week or two until you buy a new fridge.