This article will guide you on how to use the #mount and #umount command to attach and detach various file systems. You can perform this task on several media options like ISO file, NFS share and USB flash drive.
Mounting will not erase everything. The #disk does get modified slightly each time you mount it, though.
However, since you have serious directory corruption which cannot be repaired by Disk Utility you need to repair and replace the directory before it can be mounted.