He can't.

The court's ruling means biden personally can't be charged with crimes committed in office. The ruling does not grant the executive branch unlimited powers to do anything they want. The ruling doesn't mean the courts no longer have powers over the executive branch. Courts can still block executive actions.

The ruling gives the president the same immunity that cops and ceo's have. Any crimes are considered the actions of the organization they are part of. The ruling was a terrible one, but it in no way is out of character for the american legal system.