Hello, I made a guide on Steam for people who are unable to access caves in any sort of circumstance. I tried doing it the hard way but it didn't work because my friend couldn't enter caves (he got disconnected) so this method worked much more successfully for me and my partner.
http://steamcommunity.com/sharedfiles/filedetails/?id=941973730
Just wanted more people to know about this and use it if they like it.