Where is the Freeport Necro guild?

[SPennLUE]

I spent at least an hour looking for it with these maps:

https://www.msu.edu/~oconne53/eqatlas/freeport.html
http://wiki.project1999.com/Freeport

The door to the building in East Freeport is locked and I can't find the entrance to the tunnels either in the Inn or anywhere else. I couldn't find a map with coordinates so /loc didn't really do anything for me, and not having Sense Heading is only slowing me down further.

I also tried to find video guides on Youtube but no luck.