To uninstall seaview just follow these instructions.
/debian/wheezy/non-free///install/index.html Multiplatform interface for sequence alignment and phylogeny Debian 7.0 non-free/science 1:4.3.3-3
sudo apt-get remove seaview
Which will remove just the seaview package itself.
sudo apt-get remove --auto-remove seaview
This will remove the seaview package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for seaview then this will work.
sudo apt-get purge seaview
Or similarly, like this seaview
sudo apt-get purge --auto-remove seaview
|Maintainer||Debian Med Packaging Team
|Description||Multiplatform interface for sequence alignment and phylogeny|