Change Upload Path for attachments

Hi, I’d like to change the upload path because In media library I have a throuble … so I found this guide but I can’t it to work!
http://classic.vfbpro.com/faq/can-i-customize-where-the-files-are-uploaded/

Any suggestions?
Thks in advance
Rosa

https://wordpress.org/plugins/visual-form-builder/