It starts one of two ways, either 290 votes in the House of Representatives, or a call for a Constitutional Convention by 34 states.

To give you some idea how hard this is, they recently took 15 votes to get a simple 218 vote majority to pick their own leader. The 290 vote threshhold was surpassed by the 311 vote majority to remove George Santos. That's the kind of agreement that needs to happen.

Once you get that, it moves to the Senate where you need a 67 vote majority. The Senate has been crippled now with the filibuster requiring a 60 vote minimum to get anything done. 67 on a new amendment is unlikely.

The 34 vote convention path has never actually worked, although 28 states have signed off on a new convention, 6 more are still needed.

However it shakes out, either through the House and Senate or a new constitution, now you need ratification from the State Houses and that's the tricky bit.

State legislatures will need to vote up or down on it and it takes effect once 38 states pass it.

To put this in perspective, in 2020:
Biden won 25 states, the floating EC vote in Nebraska, and Washington D.C.
Trump won 25 states + the floating EC vote in Maine.

So to get an amendment passed, you need all of one side + 13 from the other side.

Want to ban guns? All 25 Biden states +13 Trump states.

Want to ban abortion? All 25 Trump states +13 Biden states.

But it's not that easy either...

Remember, the vote is done by statehouses, and of those 25 Biden states, 6 are Republican led.