εἰρήνη would normally be translated שָׁלוֹם ὑμῖν -- the dative as used here would be translated with לָ and the 2nd person plural with the ending כֶם added to the preposition.

However, there seems to be some debate about when this became a common greeting. For example, see How ‘Shalom Aleykhem’ Originated and Why It Doesn’t Appear in the Bible