Answered by Shaykh Rami Nsour
Question: Please I have this question on how to convert back to islam, I want to know the words I will need to say when I want to convert back to islam and how to do it. I want also to know what should I do for jahnaba after meeting with a woman. Please advice.
Answer: May Allah accept your tawbah (repentance) my dear brother. If you would like to convert back to Islam, once you have the firm belief that Islam is the religion that you want to follow, then you are at that moment a Muslim again.
Once you have that firm belief, then you can take a full shower (ghusl). You would make sure that water reaches all your body and that you rub that water with your hand or a cloth. You would also have to intend that you are washing for a ghusl.
To announce your Islam, or return to Islam, you should pronounce the testimony of faith (sha-ha-dah) where others can hear you say it. You would say, in any language or Arabic, “There is nothing worthy of worship except Allah and Muhammad is the Messenger of Allah.” In Arabic it would be “La illaha illah Allah, Muhammadun Rasul Allah.”
The washing (ghusl) after meeting a woman is the same as a ghusl for shahada. You make sure that water reaches all your body, you rub that water on your skin (lightly) and you have an intention to that it is a ghusl.
May Allah accept your actions.
Rami Nsour
http://seekershub.org/ans-blog/2014/05/22/conversion-to-islam-and-how-to-remove-major-ritual-impurity-maliki/