Follow the guide and you'll see it is pretty simple.
There are some issues that make things more difficult.
1/ Lack of imagery
and for me the main one
2/ When a machine has rubbish test modes, making lamps and reels difficult to work out, although it's still normally possible to finish a layout.
Other issues can be setting up a machines reels, meters, doors and security in particular, but you can seek advice or look at other machines of the same tech, to get most issues sorted.