You will have to get married under the provisions of the Special Marriage Act.
Following steps are involved:
NOTICE OF INTENDED MARRIAGE
A notice has to be given in writing in the form given below to the Marriage Officer of the District in which at least one of the parties to the marriage has resided for a period of not less than 30 days immediately proceeding the date on which such notice was given.
The notice given is then published by affixing it in some conspicuous place in the office of the Marriage Officer, and before the expiration of thirty days from the date on which the notice was published any person can object to the marriage that it would contravene any of the conditions necessary for the marriage.
After the expiry of thirty days from the date on which the notice was published the marriage may be solemnized.
PLACE AND FORM OF SOLEMNIZATION
The marriage may be solemnized at the office of the Marriage Officer or at such place within reasonable distance as the parties may desire upon payment of such additional fees as may be prescribed.
The marriage may be solemnized in a form, which the parties may choose to adopt.
However, no marriage is complete and binding unless each party says to the other in the presence of the Marriage Officer and the three witnesses in any language understood by the parties, I_______take thee________to be my lawful wife (or husband)
CERTIFICATE OF MARRIAGE
After the marriage has been solemnized the Marriage Officer shall enter a certificate in the Marriage Certificate Book and this shall be signed by the parties to the marriage and the three witnesses and this shall be conclusive evidence of the marriage.