Unfortunately we do not really have a guide at this stage, and legato on localhost do not work the same way as on PC.
Another user tried to adapt Legato for a Ubuntu (and succeeded) but all his changes are not yet merged into the mainline.
Overall though it would not really be recommended to install on localhost as it would start managing your users and reboot from time to time, which would not be that comfortable.
The closest thing to a guide that we have is a virtual platform …
What I mean is that it is non-Sierra hardware and you can see the things that legato relies on to work properly.
It’s not really documented but if you download the ‘Legato Linux’ from http://source.sierrawireless.com/ for wp85 or wp76, there should be a
meta-swi folder in there with a
common section and
meta-swi-virt that are used for this virtual platform along with common yocto and meta-openembedded repositories.