Here is how Nortel do it, ripped from the release notes.
You will need the bootcode and operating code files in the default directory of a tftp server, and to set an IP address on the management ethernet port on the SSF card.
Upgrading the boot flash image
This section shows an example of the input required to upgrade the boot flash
image in your Passport 8000 Series switch and shows the command line interface
output as the upgrade is performed:
monitor# boot tftp

80b3120.img
Loading p80b3120.img with tftp from 10.10.10.11 ... 672522
to 1016376 (1016376)
Starting at 0x10000...
################ 8K CPU BOOT FLASH Update ################
File p80b3120.rom found in loaded image
File size: 62744 bytes
Number of flash sectors to be programmed: 10
Do you wish to continue (y/n) ? y
erased 10 sectors of bootflash
programmed bootflash
Verifying new BOOTFLASH Image
62744 matches, 0 mismatches
Update complete!
Press return to reboot
/flash/ - Volume is OK
Loaded boot configuration from file /flash/boot.cfg
Press <Return> to stop auto-boot...
WARNING: You are about to re-program your Boot Monitor
FLASH image. Do NOT turn off power or press reset
until this procedure is completed. Otherwise
the card may be permanently damaged!!!
Copyright (c)
CPU Slot 6:
Version:
Creation Time:
Hardware Time:
Memory Size:
Start Type:
1998-2001 Nortel Networks, Inc.
PPC 740 Map B
3.1.2.0
June 11, 2001, 16:07:01
NOV 01 2000, 10:26:39 UTC
0x04000000
cold
Upgrading and downgrading the software 13
Release Notes for the Passport 8000 Series Switch Release 3.1.2
Upgrading and downgrading the software
• To copy the configuration file currently used by the switch in memory, use the
following command:
save config file /< device>/< config file name>
• To copy the configuration file specified by the boot.cfg file, use the following
command:
copy /< device>/< config file name> /< device>/< backup
config file name>
where:
device is flash or pcmcia.
• To upgrade the Passport 8600 switch CPU with the version 3.1.2 software
image:
a Copy the file from the tftp server to the flash or PCMCIA card using the
copy command:
copy <tftpserver IP address>

80a3120.img /< device>/
p80a3120.img
b To ensure the image is successfully copied, boot the image using the
following boot command:
boot < tftpserver IP>

80a3120.img
c If the image successfully boots, modify the boot.cfg file using the
following bootconfig options:
config bootconfig choice primary image-file < device>/
p80a3120.img
where:
device is flash or pcmcia.
Caution: Before you upgrade or downgrade the switch software, it is a
good precaution to make a copy of the switch configuration file specified
in the boot.cfg file.
I like Scott's method.
EB