Put the generic SRD in the CDROM drive in the system (or in a drive on the network you can reach)
On the actual agent you want to create the custom SRD run...
C:\Program Files\Symantec\Backup Exec System Recovery\Agent\ModifiableSRD.exe
Follow along the wizard. I always create an ISO image in the end an burn it to CD on my workstation. The hardest part can be trying to figure out which drivers you need. Once you find them and create the new SRD you just need to test it.
Hope that helps,
/RB