1) Quit Remote Buddy if it is still running (check in Activity Monitor 
- you can also quit Remote Buddy there), so that all files can be 
deleted (you usually can't fully delete an app while it is running).

2) Delete Remote Buddy.app and empty the trash (the dock will often 
keep aliases, which would then still point to the trash, which may 
contain an incomplete copy)

3) Download Remote Buddy from

http://www.iospirit.com/remotebuddy/download/

and install it manually by dragging it over to /Applications.

Best regards, 
Felix