I don't have personal experience with soul retrieval. However, you may find some useful information by checking out the channel "WildGratitude" on YouTube. Stacey Couch is a well-educated shamanic practitioner who has several videos about soul loss and soul retrieval. It may be a good place to start. :)
https://m.youtube.com/channel/UC6WIZJVT9iNUFgXl8HViGdg
Peace&Love