Soul retrieval is an ancient method for retrieving parts of your soul, and is explained on the Shaman Links article on Soul Retrieval. Its important that the healer who wishes to perform this healing on others is adequately trained. Its normal for a shaman or shamanic practitioner to learn directly from the spirit world, so the power of the training is less about the method itself and more about how to do the soul retrieval in the most healing way for the client.
When a person receives a soul retrieval they can feel very vulnerable, both before and after. A good training in soul retrieval will teach the healer how to protect and honor that vulnerability. It will teach how to relate the story of the soul retrieval in the most healing way. There are issues that can come up, so a healer needs to be trained in after care. Whether they offer after care or not, they need to be able to recognize when its needed and find the client support if it is needed.
Sandra Ingerman is an expert on the subject of teaching soul retrieval and has written an article on what to look for in a Soul Retrieval Training for people seeking training. People seeking to be healed can use it as a reference for what they might like to see in their shamanic healer:
How to Find an In Depth and Comprehensive Soul Retrieval Training by Sandra Ingerman
Sandra has approved any person teaching on the website Shamanicteachers.com, so any Soul Retrieval Training listed meets the criteria from her article.
A good teacher is one that knows how to handle all of the issues that come up in a Soul Retrieval training. They will create a powerful environment for the work, and know how to lead you through the important issues.