Disconnect the negative cable first and make sure it does not come in contact wiht anything.
The positive cable has a $200 fusible link so be extra careful when removing and installing. After the cable sare off the battery retainer is pretty easy to remove. Installation is reverse. I cannot strest how careful you need to be withthe positive cable.

What about the radio code. It has something like a fuse box on the side

The radio code is usually entered into the radio itself. It can be frustrating to do, so if you need further help , let me know. You will have to get the code from a dealership if you don't know it.