NCR unix system v/386 release 4 recover root password

Dear All

we have NCR 3455 system from long time as attached all information for server (images) ,
so we need your help to assist us to get root password which lost it , really we appreciate your efforts if you can send us the procedure for resting the administrator (root) password

which this server handle data base application writing in COBOL language

Actually i try to mount the HD to Centos 5.6 but it cant recognize the UNIX file system type (GNU HURD or SysV) , so I cant reach to passwd file to edit it to reset password . for that reason i send you this e-mail and i hope if you can gently guide me with simple procedure how i can mount the file system (GNU HURD or SysV) on Linux system or which OS UNIX / Linux even Live CD could help me to recognize this type of file system really I need solve this issue because need to add network printer to this server but I don't have privilege for that till get root password .

Note:

we have SCSI to USB converter which we can connect the HD extrnaly to my laptop

P?riph?rique Amorce      D?but      Fin      Blocks      Id     Syst?me
/dev/hdb4    *                1             523    4194157+ 63    GNU HURD or SysV

your fast response and concerns highly appreciated

Displaying

Best regards,
M.Saad