Well when you repot with any plant it is stressing....but what you have explained sounds right and exactly what I do with my plants (green thumb except apparently with a weed, I've even raised spider flowers which are related to cannabis- also a 'weed')... making sure the soil is very dry will let the unattached soil fall away...but keeping enough to not let it be lacking from current nutrients and moisture. Anyone want to back that up....he is worried! as any of us would be. ha.