Okay hear me out first, yell second. I know there are a lot of posts already answering what your thinking I am asking, but what I really want to know is how can you convert it from just some class and jar files into being bukkit format? I want to get things like buildcraft going on my server and I know there isn't a bukkit vers without rolling back, and I wanted to know what all one has to do to a mod to get it to talk with bukkit. If someone has a link or a breakdown on doing this, then maybe I can write up a java script to do it for you if it's that simple. I am not sure what all needs changes or added code. So if anyone knows or can point me in the right spot please do help.
First of all you need to decompile BuildCraft and get to understand it's code. Then you'll need to learn the Bukkit API and the Spout API. Then you'll need to re-write it somehow using the Bukkit and Spout API. It's really takes ALOT of time and effort.
Like @1lann said, you'd have to completely rewrite the mod and make it fit the Bukkit API. AND you can't create some of the stuff in BuildCraft with Spout yet.