This can be a rather complex process, but some people from outside US have registered and sucessfully complete a Kickstarter project.
The main example is
"Xenonauts" (spirtitual successor of UFO Defense). Chris, the main lead of the project, is based in London, and with the help of a US lawyer, which has follow the project from the very beginning, they managed to register successfully on Kickstarter, and Chris had full access of bank account.
However, it costs him a thousand of dollar for this (but the
Xenonauts Kickstarter bring 150 000$ on the table).
I'm not saying it will be easy, but you can mail
Chris, he's a really cool guy, and I'm sure he can give you some hint about his (long) journey to Kickstarter.
The next "direct" solution is to go to
Indiegogo, which is the "international" version of Kickstarter, but less known.