How to Backup and Restore IOS of router?

How to Backup IOS of router?

Step 1 : Assigning IP address to router

Step 2 : Assigning IP address to server

Step 3: Checking the IOS flash file on router and backing up to tftp server

Router#sh flash

Router#copy flash: tftp:

Backup file on TFTP Server...

Removing IOS from Router

Restoring IOS