On the router you are wanting to change the IOS version for copy the IOS to the flash: storage of the router.

In our case I have the IOS file on a USB pen, so first I get the exact filesystem name that the USB pen appears as using:

show file systems

The filesystem for a USB pen should either be usb0, usbflash: or something similar. In my case it was usbflash. When you have the USB naming convention copy the image using the following command:

copy usbflash: {MYIOSNEW} flash: {NEWLOCALNAME}

Bow that the image is copied enter config t mode using the following:

config t

Clear all boot operations configured inside of startup-config:

no boot system flash

Now change the boot rom from inside of config terminal:

boot system flash {NAME_OF_IOS_COPIED_2_FLASH}.bin
boot system flash

Save the changes:

copy run start

To reboot into the new IOS reload the router with the following:

reload

Once the router has fully reloaded you should be back online with the newer IOS running.