Hi,
Well, for the settings of the custom field, there is a screenshot of what to do in there, so you just have to do the same.
And for the code modification, it's a simple copy/paste. Also, when you save the change, it will be stored as a view override. And you'll have a button you can click on to delete the override in order to get back to the default display. So you can easily do your test and if you mess up, you can revert.
For the translation override, it should be quite simple too.
We sure can do the modifications for you as a custom work. But you'll spend more time talking to us by email than actually doing the changes yourself. I would recommend you try out once and let us know if you have an issue. We'll be happy to tell you what is wrong if you can provide screenshots of what you did.