the same way youd install any deb. perhaps something like this:

download the deb
copy it to MyDocs
open a terminal
devel-su
dpkg -i MyDocs/n9-button-monitor*.deb
apt-get -f install

open a terminal
devel-su
apt-get remove n9-button-monitor




to customize it, open up redak, or your favorite text editor, and edit /home/user/.config/n9-button-monitor.ini