Quite frankly, you don’t. The Orishas of your head choose you at birth. You do not choose them. You cannot force any Orisha to take you by doing any ceremony or ritual.
If your head is Shango, you may kill a thousand enemies in battle and put all their heads on a pike, bathe in their blood, and give them to Ogun with as much gusto as you can muster, but you will still belong to Shango, and not Ogun. Ogun will be happy for all that you give him, and may help you and give you all the gifts of the Earth, but your Ori is still as attached to Shango as it ever was.
It is best to make peace with the Orishas of your head, and not be so hot to escape from them just because they seem inconvenient to you at the moment. Learn them, and embrace your connection to them. Be grateful to them for the gifts and guidance they have given to you. Love other Orishas as much as you like, but don’t try to cut off your head because you think another is more convenient.