You can upgrade Popup Builder plugin via your FTP, manually, if you wish!
Please, follow some easy steps to get it done!
The example is for the Gold version of Popup Builder, so you can do the same for other packages. ;-)
1. Right click on the zip file of the Popup Builder Gold package you have, and choose "Extract here"
2. A folder will appear which you should Copy
3. Connect to your FTP account
3.1. How to find your FTP Credentials
The creation of FTP credentials differ according to the hosting provider.
So, to get your FTP credentials you can refer to the following links:
4. Go to your WordPress folder => wp-content/plugins
5. Paste the copied folder here, and you'll see "popup-builder-gold"