I've been involved with it since the beginning, when the process was less formalized then it is now, so I don't know what the steps would be for someone just st

I've been involved with it since the beginning, when the process was less formalized then it is now, so I don't know what the steps would be for someone just starting the process right now. However you need to register a claim with the trustee handling the case in Japanese Court. I was under the impression that the window for initiating a claim under normal channels has passed, but I have heard of other claims still somehow being recognized. Beyond this second hand info I couldn't help you. As I suggested to another commenter, check out r/mtgoxinsolvency on reddit. Regarding the vote, the answer is yes - but you cannot vote without having an approved rehabilitation claim, which confers a claim balance that weights the impact of your vote.