2001 transfer case work with a 2003?

[03 silverado lq4]

I have a 2003 Silverado 2500hd that came with the 6.0/4l80e. I belt the engine and was planning a duramax swap so I sold the original transmission and transfer case. Then I changed my mind and decided to put another 6.0 in it, I found an engine trans and transfer case out of an 01 but the donor truck had the auto 4x4 button where as my 03 had the push button without the auto option, so my question is what do I need to do to make the transfer case work with the truck?