Hey, sorry to bump such an old thread.
I am having the same problem with my Advan A3A's and I don't know how to split them.
I am from Canada so shipping them to NZ is pretty much out of the question for me.
I'd appreciate any help.
Thanks in advance.
P.s. This is the only place I could find info on splitting welded 3-piece wheels. I tried Wheelwhores and have had no luck over there either.