How do you convert magnesium chloride to magnesium?

Since the property wasn't specified (better for what?), I'll just base the answer on what I like more. Although magnesium chloride has all kinds of practical uses, personally I'll take the magnesium....

Magnesium has only one oxidation state which is +2 so other magnesium ion is not possible and hence its oxidation state is not mentioned, in case of transition metals as iron more than one oxidation...

magnesium

Yes.

Dissolve it in water