I really need some fast help with Adobe Illustrator-how do I redo existing type in an .eps file?

I am the sales & marketing volunteer with a small community theatre and am trying to create an image to be used on a souvenir mug. I asked someone to create a .eps file with the images I want but they used the wrong font. Can I cut the main section out and paste it to a new doent then add my own type? or just clear the current type and change the font?