Rebels to replace one with a ME king (7)

I believe the answer is:

rameses

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'king' is the definition.
(I know that Rameses is a king)

I cannot understand how the remainder of the clue works.

(Other definitions for rameses that I've seen before include "Egyptian king" , "Name of several ancient Egyptian rulers - ear mess (anag)" , "Mere ass (anag) - one of eleven pharaohs" , "old ruler?" , "Egyptian pharaoh" .)

I've seen this clue in The Times.

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