Shipping estimation from lbs to kgs?

Hello
could someone help me change the shipping estimation pop up windows from lb(s)) to Kg

thank you

Get into /includes/extra_configures/shipping_units.php

define('TEXT_PRODUCT_WEIGHT_UNIT','lbs');
define('TEXT_SHIPPING_WEIGHT','lbs');
define('SYSTEM_WEIGHT_UNITS','lbs'); //(options: 'kgs' or 'lbs') 

Get into /includes/languages/classic/english.php or your override copy

define('TEXT_PRODUCT_WEIGHT_UNIT','lbs');
define('TEXT_SHIPPING_WEIGHT','lbs'); 

kobra:

Get into /includes/extra_configures/shipping_units.php

define('TEXT_PRODUCT_WEIGHT_UNIT','lbs');
define('TEXT_SHIPPING_WEIGHT','lbs');
define('SYSTEM_WEIGHT_UNITS','lbs'); //(options: 'kgs' or 'lbs')

> Get into /includes/languages/classic/english.php or your override copy
> ```
define('TEXT_PRODUCT_WEIGHT_UNIT','lbs');
define('TEXT_SHIPPING_WEIGHT','lbs'); 

thank you I entered into that exact folder and here are the file names.

bmz_image_handler_conf.php
bmz_io_conf.php
email_use_8bit.php

enable_error_logging.php
enable_error_logging.php
media_manager.php
pci_patch_13x_search.php
security_patch_v138_20080919.php
security_patch_v138_20090619.php

I am using lATEST zEN CART

thanks

Sorry - /includes/extra_configures/shipping_units.php
Must be from an addon
Edit the english.php file