Try to avoid being relient on amendments to third party contributed modules.

Do make modifications to the contrib module, create a patch containing your changes, and file a feature request or bug report with your patch attached.  However,  in case your patch is not commited to the module by it's maintainer, it's best to also make those modifications through a seperate module.

• You will need to add the amendments in again when you upgrade to a new version of the module

• Create a new module with all the overides you want to make to the contrib module
• Use hooks to overide the contrib module's logic
• Use the theme system to overide it's output 
• Use Locale system to overide it's interface text