Add new wishlist feature without updating all?

Hi. I'd like to use the new wish list feature, however i've tweaked various files of hikashop since i got it months ago to better customise it to my website. I'm worried that a full update of it will overwrite some of these files, breaking my website. Is there a way to just add the wish list feature without affecting the rest of the files?

Actually, please disregard this request. It was a waitlist feature i was thinking of which is already in my version of hikashop.