Arya Samaj, a religious organization founded by Swami Dhayananda Saraswati (1824-1883) could offer help. This organization offers service for procedural conversion to Hinduism. This conversion practice was originally started by the founder as early as in 1877 to bring back such of those Hindus who had been converted to some other religion by choice or by coercion, who were subsequently willing to come back to Hinduism.
The procedure involves a vedic purification ceremony Called "Shuddhi Karma".
One who wants to convert to Hinduism can approach AryaSamajTemple (existing at several places in India), make a written application along with an affidavit stating that he/she is agreeing for the conversion based on his/her free will, along with proof of age and residence signed by the applicant along with 2 witnesses. The Shuddhi Karma (purification ceremony) involves conducting a "homam" (a typical Hindu ritual done in front of fire) involving chanting of certain Hymns from the Vedas by the applicant, as guided by a priest. It may take about one to one-and-a-half hours to complete the ceremony. After the purification ceremony, a Certificate of Conversion to Hinduism isissued to the applicant.