How to I switch hard drives?

My Toshiba Satellite m115 computer has been to hell and back (the sound was broken when we had the fan fixed, corners are broken off, etc) and rather than buy a whole new computer when my hard drive is perfectly good I bought a different computer that's the same as mine. I want to just switch out my hard drive so I don't lose any of my information but I'm told there is more to it than just the 2 screws to swap them out? Any help would be great!!