Congratulations to your wife not only for her new mini but for a great husband as well.
As for updating his papers, he is AMHR only so you will need the 4 pictures (each side, front and back) taken on a level clear surface, driveway, barn isle, something like that. They need to see all four legs clearly. Then you should have either a transfer paper or the actual papers will be signed to transfer him. Also because he turned 3 on March 31, you will need to get his measurement and also on the registration papers will be a place to take him permenant. You can do all of this at the same time. You can also get a work order that will tell you the cost of it all from the AMHR website, www.shetlandminiature.com .
If you have other questions, there are a lot of folks on here that can help you out.
Good luck and mini happy days ahead for you both.
Karen