How can I do that?
I have followed this https://help.ubuntu.com/community/HybridGraphics but it didn't work
I'm getting the error at boot that the /sys/kernel/debug/vgaswitcheroo/switch don't exist , so the problem seems to be that the /sys/kernel/debug don't exist when the grub parameters are processed and it is created after the grub parameter processing.
So far I have made an alternative method, which works. In rc.local I granted full access to my user to /sys/kernel/debug then also to /sys/kernel/debug/vgaswitcheroo/switch and then I have made a simple script to switch the graphics to intel and putted it in ~./confif/autostart. The script is executed every time I log in to gnome. It's working however it would be nice if it worked at boot, as is described at that help.ubuntu.com page.