Simple; move/export the minecraft
folder from /var/games/minecraft
to your desired destination, and create a symbolic link in its place using
ln -s /path/to/new/destination/location /var/games/minecraft
Permissions afterward could/might be an issue afterwards depending upon location and use case/scenario.
EDIT: There is also a mineos.conf
file located in your /usr/games/minecraft
directory that you should be able to edit in order to change the base directory’s location.