Power switch on ds lite is jammed

This morning my son was playing with his ds lite. The battery wasn’t working properly so being the good father I am, I bought another battery. My son wanted to replace it himself, so I gave him my toolkit (which I thought only had Phillips and flathead bolts) I left to get dinner, but when I came back, he opened the entire bottom cover. I closed it again, replaced the battery but when he went to turn it on, the power switch was jammed. Does anybody know how to fix this?