trouble with overrides and multiple addons

i dont really know how to override i dont understand, http://www.zen-cart.com/content.php?228-understanding-the-override-system for example what if i have 2 header.php or english how can i override that one, example includes>languages>your template>english

i just want to install http://www.zen-cart.com/downloads.php?do=file&id=75 to my free zen cart denim template but i dont know how to override etc like my admin > orders i already have orders do i need to copy some word etc

In the case of the mod you mentioned, you would go through the mod folders, changing the name of any folder named YOUR_TEMPLATE to the name of your denim template's folders, and change the name of the YOUR_ADMIN_FOLDER folder to the name of your admin folder. Then upload the folders and files according to the instructions.

YES BUT SOME of the files, i already have one, and when i compare the two files with the same name, most of t he code are diff their is no way i can merge the two, how to use t he override

Are you saying you already have installed other mods which modify some of the same files as the Tracking mod does, or your custom template did ?

denimtemplate>include>language>yourtemplate>english
same with
package track>include>languages>yourtemplate>english

i tried to merge the two but their is so many to change, i decided to override, how can i do that do i need to make a new folder include with complete files inside etc etc > language with complete files inside etc etc>

and also the tpl_account_history_info_default do i need to get the tpl_account_history_info_default to my include>template>template default>template and merge them

If you have two templates or mods that both contain an override of the same file, you will have to merge them. There is no other way to have them both work; if you were to have one override the other, the second one would not function correctly.

To merge two customized versions of a file, you first need to identify all places where each of them differs from the original. Then you can merge the two together, bringing all custom code into the final result. If both of them modify the same line(s), you will have to understand exactly what they are doing and why in order to make a combined version. In some cases, it will not be possible to have both function at the same time.