Rewrite Magento core files

Question

I have a Magento 1.9.3.1 website in front of me right now in which the core files have been edited

( THEY HAVE COMMITTED A SIN!!! ).

Anyway I have figured out which files they have edited and I am currently working on removing all those custom lines of code.

However I need to keep the functions which have been added in the website but I don't know what I should do exactly or where to place them.

Is it as simple as placing the files in local or community? ( local = specific for this website. community = from the web and not specifically for this website ). And does this count for all the files? So right now I've found all the files they edited, these are the files :

1. app/code/core/Mage/Catalog/Model/Product/Type/price.php
2. app/code/core/Mage/core/model/Email/Template.php
3. app/code/core/Mage/Customer/Controllers/AccountController.php
4. app/code/core/Mage/Customer/model/Customer.php
5. app/code/core/Mage/Customer/model/Session.php
6. app/Mage.php

Sadly I do not know if I should simply copy paste the code and add the lines of code in the custom liberary. I did google it though but I keep ending up at theme template posts...

Could you tell me where I should put the new files? and maybe if possible explain it too, And in case I am doing this completely wrong, please tell me.

Answer 1

Of course, it's forbidden to change or update the core files, so what you have to do is to rewrite all these core files.

app/code/... will be rewrited in local codePool.

app/design/... will be overrited in current theme.

Now according to this rules, your files will be rewrited of course in local.

You have good This Inchoo explanation for rewriting blocks, helpers, controllers, etc...