I'm trying to create a hook to add in custom wording to my 'add to cart' form submit button when the status of a commerce product is disabled. I'm using Commerce 7.x-1.4 and by default the wording on the form submit button when the product status is disabled is 'Product not available'. I'd like to add my own wording. I'm not a developer so am unable to write the hook function myself, any help would be greatly appreciated.