Computer question on email?

I am new to computer no mean comments please, when the company set up my computer, they put my husbands name on the email, ex. tom jones @ comcast .net. I want to change it to my name,, and can not figure out the easiest way to get this done. Please help if you know an easy way to do this. People that do not know me then assume my name is Tom when i email them to ask about something.I want to change it to ex. Julie Jones@comcast.net.