The Prophets Order to Perform Hajj At-Tamattu'
So when he wishes to make ihram and is making Hajj-ul-Qiran, having brought the sacrificial animal with him, he should say: labbaikallahumma bi-hajjah wa ‘umrah (Here I am O Allah making Hajj and `Umrah). So if he hasn't brought the sacrificial animal - and that is better - then he says talbiyah for `Umrah only and that he must do, saying labbaik allahumma bi-`umrah. So if he has already made talbiyah for Hajj only, he cancels that and makes it into an `Umrah - as the Prophet ordered that and also said: “I have entered the Hajj until the Day of Judgment” and he joined his fingers together (as in the Hadith that has preceded).He also said: “O family of Muhammad - whoever from you makes Hajj, then let him say talbiyah of an ‘Umrah in Hajj ” and this is At-Tamattu' of `Umrah with Hajj.
And if he wishes when making talbiyah he may state a condition to Allah fearing that which may prevent him (from completion of the Hajj) whether illness or fear - saying as the Prophet taught: allahumma mahilli haithu habastani (O Allah my place is wherever you prevent me).  So if he does that and is then prevented or becomes ill - then he may leave ihram of the Hajj or `Umrah - and there is no re-compensatory sacrifice due upon him and he does not have to do the Hajj again, except and unless it was his first Hajj - then he has to repeat it.
There is no special prayer for ihram, however if it is time for prayer before ihram, then he should pray and then put on ihram following the example of the prophet of Allah who put on ihram after prying Dhuhr.