If you understand how distillation and reflux work as well as how to use a separatory funnel, what else do you need to know to follow a guide? You don't really need theoretical knowledge if the guide is well written. Maybe a good base of common sense, attention to detail and some previous technical experience helps but I have seen total drones being shown a process and not 4 days later repeating it perfectly. Like I said, if you know how to use a frying pan and oven, you just need a good cookbook to make a panty-dropping dish, not years of cordeon blue schooling.