OK - you asked so totally on your own head here are some clues .... based this as being on Windows but you havent said either way ...
run <installpath>\netbackup\bin\NbDbAdmin.exe
Log in with a password of nbusql
Select the NBDB
Go to the Tools tab
In the Unload section select Export
Browse to a directory where you want the information and choose between schema or data and schema
Click OK
You now have the schema and the login password
Read the reload.sql file - it gives you a good idea of what everything is and the structure.
Hope this helps but again this is for informational purposes only and any issues cause are you own responsibility - also advise a full catalog backup prior to you first attempt to connect to it.
Having said that - if it does what you want it may be of interest what results you get so update this thread or drop me a line with what you acheive