I don't have a DIY manual yet. I have shot many videos for other automotive things and will try to get one in the can within two weeks. The general jist is to open the case, remove the 120V transformer with it's two white electrical plugs and swap in a Recom 21000128 from Digikey.com. Cutting off the two plugs and soldering the four wires to the cut pigtails is all you really have to do. Just be sure to use correctly sized 1/8" or 3/32" heat shrink to keep everything safe. Do NOT use wire nuts. The red POSITIVE wire for the DC output from the Recom power supply goes into the position on the smaller plug that is CLOSEST to the AC input plug. A picture of this detail is posted in the next post.
I went as far as sourcing the JST plugs to make it perfectly plug and play along with the correct receptacles. Those part numbers are below. This method requires you to have the proper crimping pliers and dies which not too many people have. Plus, the 18AWG red and black DC output wires from the Recom power supply are too large a gauge to crimp neatly onto the tiny receptacles for the DC input plugs so I soldered the receptacles on. It took a while to figure out how to solder them on and keep the union small enough to be able to slip into the small white plastic housings. Cutting off the plugs with an inch or two of wire and soldering them to the Recom power supply is the best way to do this mod.
Power supply: Recom 21000128 (RACD03-350) http://www.digikey.com/products/en?keywords=21000128
Here are part numbers ONLY IF you want make a plug and play assembly which is not necessary in my opinion:
DC output metal crimp-on terminals: SXA-001T-P0.6 (2 required per evse, Digikey p/n: 455-1904-1-ND)
DC output 2 position JST plug: PXARP-02V (1 required) special order from JST
AC Input metal crimp-on terminals: SVH-21T-P1.1 (2 required per evse, Digikey p/n: 455-1133-1-ND)
AC Input 3 position JST plug: VHR-3N (Digikey p/n: 455-1184-ND)