You apparently originally installed Sublime Text from a third-party source or PPD. On the command line, run
sudo apt-get remove sublime-text-installer
to remove the old package, then switch to the directory where you downloaded the new
.deb file and run
sudo dpkg -i sublime-text_build-3103_amd64.deb
to reinstall from the official source. This method will not remove your custom settings or packages. However, depending on how you set up your previous installation, you'll need to use the command-line shortcut
subl instead of
Finally, I recommend reading through my answer here for information on making Sublime your default text editor, if you haven't already.