Hi Henry,
We don’t have a guide for this specific use case, but you can add it to the Ideas board under the Hitchhikers Platform & Documentation category.
The approach you could take is to combine this guide on customizing map pins with these instructions on how to use SVGs for the map pins (note this refers to the outdated vertical-map template but you’re probably using the vertical full page map template).
Let us know if this works and if you have any questions!