I looked into this too. I decided it would probably be way too complicated for me. It isnt anything like loading an OS on your home PC. Once you get these resources, it will likely be a very painful process. And for phones like the 6700, the builds are ported from other phones. I dont think there is a resource pack for the Apache... but... maybe you can come up with something. Anyway, here is the place you need to start:
http://msdn.microsoft.com/en-us/embedded/aa731407.aspx