The "standard" method of getting NetBSD/pc532 onto your pc532 is
via the console terminal and using the downloading parts of the
ROM monitor.  As such, usually another computer has the distribution
on disk and is connected via a serial line to your pc532's console
port.  A terminal connected to the attached host computer is used
to access the pc532 console via a terminal program.  

You may need to find and read the documentation about the ROM monitor
download command and other low level comands.

Other methods of getting NetBSD/pc532 on your pc532 may include 
SCSI tape or SCSI floppy disk or cloning a disk on a system
already running NetBSD/pc532.

If you have some operating system already running on your pc532,
you can use that OS to get NetBSD/pc532 on a hard disk much easier than
with the ROM monitor.  (NetBSD/pc532 was developed from Minix/pc532
until it was self hosting.  You can run NetBSD and Minix or other OS
off the same disk.)