Becoming Self-Employed in Rio (Rio de Janeiro)

I'm trying to become self-employed which requires registering as a MEI Microempreendedor Individual. The process is very easy for Brazilians or if you have citizenship but for those of us who only have Residency, it's a little harder. Our CPF doesn't work with the registration website and I've been going around in circles being sent from place to place only to come to a bit of a dead end. Has anyone done this? I would be grateful for any information about how you achieved it. Thanks.