When you are ready to apply the configuration changes you previously saved to a file, copy the file (myconfig in the example) to the startup configuration. The changes take effect after the device reboots.
Enter the copy command in privileged EXEC mode. Specify the file name as the file URL followed by the startup-config keyword.
device# copy flash://myconfig startup-config This operation will modify your startup configuration. Do you want to continue? [Y/N]: y