How to add warranty field to OC 1.5x

How to add a custom warranty field to my opencart store.

I want it should appear in the following areas:

Product Front end
Product Admin Panel
Admin Voucher
Customer order email voucher.

Thanks

This is the free Version:
Product Warranty Details Free
EXTENSION FEATURES
> FrontEnd Product Show, set YES to show on product page
> Set Product Warranty from BackEnd Product Page
> Show Warranty Details on the Product Page
> Automatically Enable/Disable xml file when Installing and Uninstalling
> Commercial support for custom theme($5)
> No core file will be overwritten
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http://www.opencart.com/index.php?route ... n_id=23950
---

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And this is the 15-Dollar Version:
Product Warranty Details
PRO VERSION FEATURES
> Multi Languages
> Show Warranty to the Product Page
> Show Warranty to the Shopping Cart Page
> Show Warranty to the Checkout Page
> Show Warranty to the Order Invoice
> Show Warranty to the Order Back-End View
> Show Warranty to the Order Information
> Show Warranty to the Order Email
> Option to show to front-end product page or not
> Customizable multi language warranty group title
> Use Pre Define Product Warranty Option
> Adding UNLIMITED Pre Define Product Warranty for use
> Set Product Warranty from back-end product edit by choosing pre-defined warranty or write your own
> Automatically enable or disable xml file depends by module status
> Free Installation on server
> Unbeatable Free Lifetime Support
> No core file will be overwritten
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http://www.opencart.com/index.php?route ... n_id=13738
---

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and there is nothing in between, or else, as far as I know.
Good Luck
Ernie
openshop.li

PS: And this was my FREE (uncensored!) Posting Number 4'000, I guess, I have to slow down on this...