upgrading k-touch v9 from android 4.0.4 to 4.2.1 -EDIT-

hi everyone,
right now, a lot of thing doesn't go well on my k-touch v9, and i want to go on android 4.2.2 instead of bad 4.0.4 Chinese android.
i have downloaded from the needrom.com site the android firmware for this specific phone, and i don't know how to install it.
i know how to go into recovery mode, and there i can update from external storage.
please, can someone give me specific instructions to install this firmware? i am really stuck and cant install alot of apps...
many thanks for answers!
Gili Shdema :-)

Edit:
i moved the .zip file to the phone, went to recovery, wiped cache and factory reset, and then did upgrade from external storage.
the phone started to do the upgrading, but then he says: "E: signature verification failed".
right after this, it went back to recovery. tried a few times and nothing happens. tried to wipe and factory reset again and no response.
hope for help!
Gili Shdema :-)

— modified on Mar 27, 2013, 6:25:20 PM