You can uninstall or removes an installed aalib1 package itself from Debian 9 (Stretch) through the terminal,
$ sudo apt-get remove aalib1
If you would like to remove aalib1 and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove aalib1
If you use with purge options to aalib1 package all the configuration and dependent packages will be removed.
$ sudo apt-get purge aalib1
If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.
$ sudo apt-get purge --auto-remove aalib1