I would recommend upgrading to 4.1.1d. Much easier to deploy and accelerate traffic.
Prior to 4.1, in 4.0 you must upgrade the core wae, branch wae, then central manager. User the recovery CD file and ftp to remote locations for upgrade.
With 4.1 upgrade central manager first, then core and branch and use recovery cd on CM and isntall using ftp to others.
copy ftp install a.b.c.d
