If the opposite person is interested then you can guide them. They need not be Reiki Channels.
Open the manual and say the affirmations, while the patient has to visualize a silver triangle and release all their memories into to it.You will be drawing the symbols on their behalf.
You can also do for others, even if they are not physically present. It is not distant healing, as distant healing is a misnomer. There is no distance between any two persons.
Visualize the person in front of you or take the photograph of the person. Do the healing. Say that the triangle moves through their chakras.
The only possibility of failure is you are doing it without their consent. You are only working through your anxiety and concern for healing the person. Therefore, it may or may not work.
Sitting next to you
So, it is better if the person sits next to you. He should be ready to release his memories. We can’t force it to happen.
Make them understand the concept and ask them to be ready to release from their memory.
Ideally, you can take the class. You needn’t be a Reiki master to do so. But, he has to be a Reiki channel then.
If he is not then ask him to be in front of you, while you draw the symbols.