denali@Ezerhardin:~$ sudo apt-mark manual ubuntu-mate-core
[sudo] password for denali: 
ubuntu-mate-core was already set to manually installed.
denali@Ezerhardin:~$ sudo apt-get remove brltty
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be REMOVED:
  brltty brltty-x11 ubuntu-mate-core ubuntu-mate-desktop
0 upgraded, 0 newly installed, 4 to remove and 0 not upgraded.
After this operation, 6,724 kB disk space will be freed.
Do you want to continue? [Y/n]