Massive change Url File download

Hi sir.
I have all my downloads with the upload file path this way:

File URL: /wp-content/uploads/xyz

I realized that first slash is making the error “Sorry, this file could not be downloaded”

I have fix it deleting first slash, so: File URL: wp-content/uploads/xyz

But…. i′ve got plenty of downloads, and changing one by one is very slow. Is posible massively change it, by editing a file o so? (just by my resposability )

The page I need help with: [log in to see the link]