http://35mm-compact.com/forum/viewtopic.php?t=12725

sudo dpkg -i --force-overwrite  iscan_2.11.0-2_i386.deb  
sudo dpkg -i  iscan-plugin-gt-x770_2.1.0-1_i386.deb

sudo echo "epkowa" >> /etc/sane.d/dll.conf