Where there is a will, there is a way! Having done, modified, redone, modified more, and redoing again, I know how much work and frustration (and sometimes expense) is involved, exspecially when you are trying to do it with birds already living in it. The better you can do it the first time, the happier everyone will be! But even the best of plans often need modification once it's in real world use. Best of luck, I'm sure in the end, it will be good. It's a learning curve, just like so many other things. The more of others stuff you look at and read about, the more information and idea's you have to work with.