What is 'Relax' when translated from English to Italian?

Rilassarsi, Rilassati, and Rilassatevi! are Italian equivalents of the English Word "Relax!" The choice depends upon whether the present imperative and reflexive pronoun are said to an audience of one (cases 1, 2) or more (cases 1, 3). The respective pronunciations will be "RE-las-SA-rey," "ree-LAS-sa-tee," and "REE-las-SA-tey-vee" in Italian.