Not quite sure...

There is a configuration file in your Ace of Spades installation folder. It's named: "config.ini" Open that up with notepad (or your preferred text-editor), and change the line that reads: "name Deuce" to "name Whateveryouwanttobecalled"

Optionally you can use this tool for easy setup.

Please, next time use the Search function located at the top-left of this page, to check if what you're looking for has already been posted.