don't know of any how to write ups but it's not too difficult, just get some measurements and some cardboard and mess around cutting and test fitting it in there til you get something that fits and looks good to you, then transfer it onto some mdf or whatever you'll use and cut it all out and assemble. just be sure to get approx. the right inside dimensions for what your sub calls for so it'll sound good. It's time consumming but not the hardest thing to do. Worth the money for a professional job but if thats not an option then just give it a try
