I second Dietpi. Very easy if you just follow the instructions for headless and if using it wireless then have to just edit the dietpi.txt and dietpiwifi.txt file to include your wire less credentials prior to first boot. There is detailed instructions on dietpi site.
Thanks, I actually have his Nuimo running on a pi 3. I think the 2 is under spec for Rooextend. Am trying to install dietpi now. If that fails I’ll give it a go anyway.