Agreed. Ousting either the president or the vice president requires 67 votes.
Hmm. If the votes were available, the crafty approach would be to remove Biden first, then impeach and remove Obama while stalling the confirmation of Biden's replacement. That would require organization and stealth. E.g., fewer than 67 GOP, so Obama thinks his Regime is safe, but some Democrat cross-overs up the sleeve. Once Biden's ousted, Obama's trapped. Well maybe not. Maybe he can pardon himself‽
There are no grounds to impeach Biden. He has committed no high crime or misdemeanor because he has no ability to institute policy.
Obama could resign at any moment and therefore he would beat removal by impeachment and that would immediately elevate Biden to the presidency, requiring no action by Congress,