What does anyone have to do to get unbanned from streaming League? Just curious.

Riot can't ban people from streaming League.

Riot can ban people who stream League from playing League. Riot can ban anyone from playing League.

I'm going to assume that what you mean is not technically being banned from streaming League, but being banned on sight (which makes streaming next to impossible without getting the account banned).

There is no simple answer, though. These punishments are so rare that Riot judges those cases individually. One case I know there is absolutely nothing that person can do... other cases it was enough to simply keep a good record and be apologetic about what got them punished. Soooo... unless you were to admit that this is related to Tyler (or anybody else that is indefinitely banned, really) it's really not possible to give a proper answer.