I generally open the zip file and drag the folder in it to my local plugins folder for the site, when it asks if I want to overwrite existing files I click yes, then upload the new files to the server using FTP. I’m a developer so I update a lot of plugins like this, especially the ones that do not have automatic updating. I occasionally see errors connecting to the update server for ACF, and I don’t know what causes it. I don’t know if there’s another way to do this, when updating from a downloaded zip this is always what I do.
