Milling down a Dually Rim

So I am looking to get into a dually project early this summer. I have found several sets of rims cheap locally to me that are not milled at all. From what I have read its the inside of the lip that is different and the overall size being 1/2" more. Does anyone have any visuals of what needs to be done so I can show a local machine shop? Finding dually rims in Canada that are machined already can be a bit tough...

You probably have better chances at calling coke and asking for their recipe.

Buck up and order a set from the states.

lol...that made me chuckle

We found a local machine shop that can do it and what needs to be done. Turns out the OD doesn't matter its just the inner lip.