Ha! You're out of your expertise here cowboy, stay in your lane. There is no such thing as expungement for impeachment. Congress can't even reverse it. They explored it with Johnson years later, (after his term he served in the House of Representatives), and in 2007 the Democratic controlled Congress examined it for Clinton, instead of going after Bush for the lies that took us into Iraq. There is nothing that can be done.
In the 1830s Congress expunged President's Jackson's censure. But that's just a rebuke. That's the only time and it's nothing like impeachment. Only you, Hannity, Alan Dershowitz and Donald tRump thinks you can expunge an Impeachment.
So, your boy, will forever be known as an Impeached President who was a complete sideshow and in over his head. Like you, in this discussion.