You can just do some string manipulation (NOTE: Unfulfilled code)
UPDATE table
SET date=
LEFT(CONVERT(VARCHAR(50),date,128),4)
+SUBSTRING(CONVERT(VARCHAR(50),date,128),7,3)
+SUBSTRING(CONVERT(VARCHAR(50),date,128),4,3)
+RIGHT(CONVERT(VARCHAR(50),date,128),LEN(CONVERT(VARCHAR(50),date,128))-10)
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