Change password on 3640 1

[Fireman]

Hi All,
How to change a password on Cisco 3640 router? Here is a peace of configuration file that might be helpfull:
...
aaa authentication password-prompt Password>
aaa authentication username-prompt User>
enable password 7 xxxx
!
username JOHN privilege 15 password 7 xxxxxxx


I would like to change password for user john. What is the proper procedure for this and from which mode (privileged, config) i can make these changes? How can i save changes to the configurations? Thanks for help...

 

[jeter]

If you are just wanting to change the password for user john , I would remove
(no username JOHN privilege 15 password 7 xxxxxxx ) from the configuration conf t
then re-enter username John privildge 15 password ?????? This should work out find !
Oh do not forget to save ( Wr mem ) ... Just tried it on my router and this works ok .