good question. don't know once both are sworn in. i would guess that it must be through an impeachment process which would require some criminal accusation. usual would just be dump them before a 2nd run but not the case here as trump can only be in 4 years as he has already been in 4.
Before election it's likely through the party electors or party leadership nominating someone else and then voting on it, after Trump is elected if the VP steps down or is impeached then the President picks somebody and Congress votes on them.
Tucker seems to like JD Vance so that's a plus. I want to see how he debates against that gutter slut Karmela.