Hello,
For migrating CIFS, you will have to check that they want to migrate 1 to 1.
If so, you can just initiate a snapmirror of the volumes between the old filer and the new one.
You can than recreate all shares on the new system, check if they use quotas, and migrate them.
Are they ready to use a new name for the file server ? Do they use DFS for naming ?
If you do the migration in one shot, you could change the filer name or add an alias to the new one.
If not, they will have to update the way they connect to the shares (DFS, scripts, etc...)
For the migration, when they are ready, remove the share on the source system, perform a last snapmirror update, and then break the mirror. The volume on the destination will be ready for R/W.
Place the old volume offline when it's done, so people can't access it in any way, but you can still access it in the coming days if something occurs.
Regarding the snapshots, it is easily done in System Manager.
For NDMP, I don't have experience on Backup Exec, so, you'll have to go through the documentation.
Regards,
JC