1. Copy your firmware image to your usb drive using your computer.
2. Plug the usb drive into your router. You should see usbflash0: has been inserted in the terminal prompt.
3. Run the following command to copy the IOS image into the router’s flash:
router# copy usbflash0:c2900-universalk9-mz.SPA.157-3.M3.bin flash0: c2900-universalk9-mz.SPA.157-3.M3.bin
4. Verify your file is in flash by running the command:
router# dir flash0:
5. Tell the router to boot to the new image by running the following commands:
router# conf t boot system flash0 c2900-universalk9-mz.SPA.157-3.M3.bin exit copy run start
Also, if you’ve previously configured your router to boot to a specific IOS file you’ll need to remove that line from your config before reloading the device. To see what all is in your boot config run the following command:
router# show run | begin boot
Find any erroneous boot system commands and remove them using the “no” command followed by the erroneous config line like so:
router# conf t no boot system flash0 oldconfigfilename.bin copy run start
6. Reload your router to boot to the new image by running the following command:
reload# reload
7. Once the router is booted back up, go ahead and delete the old firmware image from the flash by running:
router# delete /recursive /force flash0:c2900-universalk9-mz.SPA.156-2.M2.bin
