To change a law requires both houses and a Presidential signature, or veto override in both houses.
It’s really elemental. Just read the constitution or look up School House Rock on how a bill becomes a law.
You have serious issues.
Anything passed by congress (and signed by president) can be changed by congress (and signed by president). There are no protective measures. Got that? This 2/3 change requirement is absolute BS and only an absolute fool would claim otherwise.
Congress is not bound by the measures in existing laws, it can simply rewrite them anytime.
Once day there will be Dem president and Dem congress again.
This 999 can become 9-9-25, or 20-20-20 anytime. It would be foolish to create a new tax (remember AMT for “the 20 rich families”)