1. Make sure System Preferences is not open.
2. Remove the Dasher.prefPane file from the appropriate folder. The appropriate folder depends on the choice you made when you were asked how to install Dasher as it opened the very first time. If you chose to install Dasher only for yourself, remove /Users/[your username here]/Library/PreferencePanes/Dasher.prefPane. If you chose to install Dasher for all users, remove /Library/PreferencePanes/Dasher.prefPane.
3. Remove the Dasher Daemon Login Item. To do this, open System Preferences and go to the Accounts preference pane. Select the Login Items tab, which should show you a table of your Login Items. Single-click the row that contains Dasher Daemon, then click the square button with the minus symbol directly below the Login Items table. The Dasher Daemon row should disappear.
4. Stop the Dasher Daemon process. The easiest way to do this is to log out and back into your Mac OS X user account. Another way is to use the Activity Monitor utility in /Applications/Utilities/ to locate the Dasher Daemon process and stop it.