Can anyone help me please?

I would like to daisy chain two SCSI disk units to one Sun 3/60 processor box,
only I don't have any instructions, has anyone out there done this and if so
could you answer the following questions?

I cannot see any selctors for the SCSI id anywhere on the disk units and presume
that I will have to open these up and change a link somewhere. Am I wrong? If I
am correct does anyone have any info on carrying this out?

Assuming that I overcome this problem, is there much administration to be
carried out to make use of the extra unit?

thanks for any replies

Derry