Changing uploaded pdf urls??

Hello,

I am in the process of creating a new website on Wix for my work. We are a small NGO with little budget and an out of date website so this seems like the easiest/cheapest option... I have some experience using wix but this current website I am making is proving a lot more complicated primarily due to the amount of pdf's and documents that need to be uploaded as resources.

The thing I am struggling with is this:

We have various documents that we send out containing hyperlinks that then link to pdf's on our current website. When I make the new website & upload the pdf's... is there a way to make the url of these pdf's the same as the old ones so that the hyperlinks still work? OR do I have to change all the hyperlinks in the documents to link to the new website (which isn't a problem for the new people we are sending them out to but would mean anyone who has the old copy would have broken links....)

Hope this question makes sense and any help would be greatly appreciated as it is pickling my brain right now!!

Thanks.