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How too
Forum-Index → Help → Answered → How tooIf an Everstone is given to the Pokémon when they can evolve [for instance, giving a Level 17 Totodile an Everstone and leveling it up] and it is taken off, it will evolve when it reaches the next Level.
For other methods of Evolving Pokémon such as by Stone or Trading, this Guide could be used as a very helpful resource.