An amendment can alter the text of any portion(s) of the constitution. While I agree that abolishing the Senate would be a radical change, I do not know of any restrictions which would bar it.[1] Even if this were not possible, a constitutional convention could be held to make the change.

[1] https://en.wikipedia.org/wiki/Article_Five_of_the_United_Sta...

Technically it says that "no state, without its consent, shall be deprived of its equal suffrage in the Senate" so the Senate could presumably be abolished by constitutional amendment if all states agreed. (I wonder about replacing the Senate with another legislative house and giving the existing Senate largely ceremonial responsibilities without formally abolishing it -- would that count as depriving the states of equal suffrage in the Senate?)

Presumably any amendment that would abolish or sufficiently alter the Senate would simply remove that article as well.

The phrase "the Constitution prohibits this amendment" doesn't make any sense because an amendment to the Constitution cannot by definition be unconstitutional.

Perhaps that was meant to say, it would make the Constitution internally contradict itself?

It prohibits an amendment to eliminate the equal representation of States in the Senate, but it does not prohibit either of:

1. An amendment eliminating all actual powers of the Senate, either with our workout creating some new body to which those powers are transferred, or

2. An amendment eliminating the restriction on amendments eliminating the equal representation of States in the Senate.