No federal judge has been removed by any process but impeachment.
The professors who wrote the article you linked stretch the constitution to suggest congress COULD pass a law to allow their removal without the impeachment process.
But it’s certain that would not pass “judicial review”.
Article III conditions a judges tenure on continued good Behaviour; the clear implication is that misbehavior can terminate a judges stay in office.
You need to reread it, and not give it a cursory glance.
In short, Gingrich suggested that Congress use its power to realign the lower courts to eliminate and reconfigure them.
One way to eliminate a judge is to eliminate the district that judge presides over, or change the jurisdictional boundaries that judge is allowed to rule on.
-PJ
The only Federal Judge removed in my life time is Alcee Hastings who is a US Congressman and has been for many years. A Federal Judge has a better chance of being hit by lightning than being impeached.