There isn't really any special trick to making it work. Just a lot of repitition. I wouldn't be surprised though if many of the things that you think need to be alt picked powerchords are actually alt picked muted single note rhythms that are tabbed incorrectly as powerchords. Thats assuming you're reading from tab. I'm not great at it, but its very doable, just keep on keepin' on! It'll come eventually. I've never really thought about it too much to be honest.