Yes Jessi, you will need to remove Norton prior to installing the program you plan on replacing it with. Take a look here for a link to the tool to remove it:
http://us.norton.com/...0710133834EN&ln=en_US
Bear in mind that you'll want to avoid using the Internet without an anti-malware program in place, so consider downloading the program you plan on replacing it with beforehand. That way you can have the new program up and running prior to connecting to the net to do it's first update.