Pretty all of the resource is from this article. Except my opinion
To simplify the step.
1) download http://simh.trailing-edge.com/kits/uv5swre.zip
2) unzip everything
3) create a pdp11.ini
set cpu U18
attach rk0 unix_v5_rk.dsk
3) then run the pdp11 emulator. This I assume that you installed simh already.
note: on windows you might need to copy the pdp11 emulator, from simh, to the same folder as the unix.
you should see the following. prompt
PDP-11 simulator V3.7-0
just type unix
;login:, then type root. Now you should see the familiar root shell.
But note it's not a unix as we know on linux, or bsd, or any modern unix(i think), for example there is no cd, it's chdir. And many thing is not there, or very different.
But that's unix. What cool, is that, it contain the source code for unix as well. And amazing how to stuff the OS, in a relatively small package