Here is the official process:

Most professionals looking for this image fall into two categories:

You can optionally remove the previous boot statement to avoid confusion. It's also good practice to save your running configuration.

Use copy tftp: flash: to move the image, and always verify your boot statements with boot system flash [filename] .

: Includes support for legacy telecommunications routing modules like V.150.1 modem relay for secure communications. 3. Core Enterprise Routing