I don’t think that the 8830 takes a sim card that can be changed. It’s under the cover and isn’t a user serviceable part.
I popped the back plate off my 8830 and nearly lost my SD card in the couch in the process looking for it. When you pull the battery cover off, to the left of the SD card there’s a little silver cover with a little mark on it. I think it’s under that silver cover plate.