Have the Qur'an by your side, to help recite the key verses for the person having reactions.
At times it may be difficult, but try your best to lay the person down & keep them that way.
Playing the Ruqya audio is a great help to assist you along with reciting over them.
IMPORTANT NOTE: Remaining calm is very important & makes a world of a
difference! Also know that the Jinn are not to be feared, in the case of possession.
They have no power to harm, except if Allah allows it, and fearing harm from them
is a forbidden type of fear which, falls into Shirk (associating partners with Allah).
THE KEY STEPS
Position the person flat on the floor & have someone clear the room of any harmful objects.
Seek refuge with Allah and attempt to get the person who is suffering to seek refuge as well. You may find if it is Jinn possession, the Jinn may make it difficult for them to do this.
Play the Ruqya audio to the person who is having a reaction. Playing out aloud is very good, however playing through headphones is even better!
If there is a major reaction the Jinn may speak. Avoid conversing with them! Remember reciting the Qur'an and/or playing the Ruqya Audio is the weapon against them. If the Jinn has had enough, it will leave the body by the permission of Allah.
If the problem persists and the Jinn refuses to leave or the person does not come back to a normal state, continue to play the Ruqya Audio until it occurs (the time it may take varies, every case is different). If the concern is still there, book an appointment through the Contact page immediately!
Recite the Qur'an over the person. The key is to recite the Qur'an with full conviction! Surah Baqarah is very effective by the permission of Allah. More verses are found in the link below.