Of course. When you purchase CFTicket you are given the entire source code which you can modify for your own personal use. You may not remove the copyright notice from the bottom of the pages.
The actual pages that you see are located in the /system/cfpagelets/com/cfticket/. This should let you edit anything you need.
Since we developed CFTicket, we know the ins-and-outs of it! If you don't feel comfortable changing CFTicket yourself, you can ask us. For pricing please visit our website at http://www.cornfeed.com.