OK I figured it out. Here are the steps:
1. Download the replypost-notification.xml which you'll find here
https://vborg.vbsupport.ru/showpost....&postcount=765
2. open the file just downloaded and edit it as explained in the post. Be carefull that there are two plugin in this single xml file which means that you have to edit the text for both plugin ( search for 'forumid'], array(105,83,121,110,82,112,109,101,102,72)) inside the document and you'll find two results)
3. once you edited it save the file and go to your admincp page
4. scroll down to the end and go to Plugins & Products --> Download / Upload Plugins
5. scroll to the botton and upload the previous xml file. You should see now the "VSA New Reply" and "VSA New Thread" plugin in the list.
Job Done