I've got a 200 year old house with a crawl space under one corner of the house. The entrance to that crawl space is very tight (pictured below), and I am a large man. I want to expand the entrance to the crawl space a couple of inches downward, and potentially a couple of inches to the left. The wall is granite stone construction, so i was planning on breaking down the mortar on the flat surface and removing a layer of stone. I need to repoint the walls on the inside of the crawl space, and it's currently very difficult for me to get in.
Can I lengthen or widen the hole a few inches without worrying about structural integrity?
EDIT: Added more photos for clarity. Apologies if it's still not clear, there's a lot of ductwork in the way that makes getting a good shot of it all difficult.