How does one perform ghusl before ihram for Umrah, and is it like ghusl for janabah or like wudu? And what is the intention and what are the required utterances for the two rak'ahs before ihram?

Taking a bath (ghusl) for Ihram is recommended by most scholars. It involves washing the entire body with water for cleanliness and to remove unpleasant odors. There isn't a specific method for it, but the most complete way is to perform it in the manner of the Prophet, peace be upon him.

Praying two rak'ahs (units of prayer) at the time of Ihram is a Sunnah according to most scholars, and it is not a condition for the validity of Ihram. It should be performed with the intention of the Sunnah of Ihram. Some scholars hold that there is no specific Sunnah prayer for Ihram; rather, it is recommended to enter Ihram after performing an obligatory prayer or a regular supererogatory (nafila) prayer.