I've been trying to create cc for a while and understand how to use the S3OC to clone the objects that come with the game, but how do you create something using another creators mesh? Often on simblrs I'll see "mesh by ____". What's the process of downloading an object from someone and editing it in Milkshape to make it your own (then obviously crediting the original creator)? Can you use any .package as a mesh?
FYI, I'm trying to make a bed frame and don't find any of the standard Sims 3 beds close enough to what I have in mind.

Thanks!