A very minor correction: 4. Create /usr/share/X11/xorg.conf.d90-x250-trackpoint.conf ...
this should be 4. Create /usr/share/X11/xorg.conf.d/90-x250-trackpoint.conf <--- there is a "/" missing
A very minor correction: X11/xorg. conf.d90- x250-trackpoint .conf
4. Create /usr/share/
...
this should be X11/xorg. conf.d/ 90-x250- trackpoint. conf <--- there is a "/" missing
4. Create /usr/share/