The Performance of Umrah
When you reached the prescribed Station of Ihram ( al-miqat ), make ghusl (a shower or fall washing of the whole body), and then put on the tow-piece garment of Ihram ( izar and ride), which preferably should be of white cloth. This applies to men only. A women also makes ghusl but she does not use makeup, and she may wear any clothes she has available as long as they do not display her adornments. She should be completely covered except of her face and hands. Then make your intention to perform Umrah by saying: “ Labbayka Umra ” or: “ Labbayka Allahumma Umra ” , as  follows:

Labbayka Allahumma Labbayk. Labbayka La Shareeka Laka Labbayk. Innal-hamda wan-n'imata Laka Wal-mulk La Shareeka Lak”
(Here I am at your service. O Lord, here I am. Here I am. No partner do you have. Here I am, Truly, the praise and the favour is yours, and the dominion. No partner do you have.)

Men should utter this aloud while women should say it silently. Repeat this talbiyyah frequently, and engage in the praise of Allah, in supplications for forgiveness, and in the enjoining of what is good and forbidding what is evil.