You can ordinarily update your WordPress plugins and themes from within the dashboard. If you see this on your dashboard, 

a number next to two circular arrows, you have updates pending. Click those arrows and complete the updates. 

As with any software or technology, things can go wrong and you may need to update these manually. This is possible via FTP. 

1. Download the latest version of the plugin you are trying to update. Free plugins are generally hosted here

2. All plugins come in .zip files, so you need to extract them.

3. You need an FTP client. We recommend FileZilla

4. Once installed you can now connect to your website on our server. 

5. Your FTP details are in your control panel or in the welcome email we sent you. 

6. To connect fill in the details at the top of FileZilla

7. The folder you need to work in is 'wp-content'.  Double click to open it. 

8. Open the 'plugins' folder. 

9. Rename the problematic plugin's folder. Don't delete. 

10. Deactivate the plugin from your dashboard. 

11. Upload the extracted folder from the plugin downloaded earlier. 

12. On your dashboard you need to find the newly installed plugin and activate it.