Upgrade image i.e the tar file in the root directory/ current directory of the tftp server. Go for a console or a telnet connection to the AP: go to enable mode, use command:
ap#archive download-sw /force-reload /overwrite / tftp://{ip address of the tftp server}/{exact filename with ext}
note:before going for this make sure that the ap and the laptop/desktop are able to ping each other and do not, in any case, interrupt the upgrade process once started.
