How do I go about this? The link in the faq is dead.
There are multiple ways to do it. The best is usually to hide all but part of the model and use Tool>Polygroups>Group Visible. Continue doing this until the entire model is regrouped the way you want to break it up. Then use Tool>SubTool>Groups Split to separate the model into SubTools with each polygroup becoming its own SubTool.
Another is to hide part of the model and then use Tool>SubTool>Split Hidden to break that part off. The reason why this isn’t really as good is because it’s harder to fix if you find that you’ve made a mistake or bad choice while splitting the parts off. With the polygroups method you can see exactly how all the pieces are laid out before you actually split the model.
Thank you aurick.