Matching the moodle version and plugin version.

• navigate to C:\xampp\htdocs\moodle and open version.php
• you will see a line like " $version = 2021051703.04; " . copy the verion (2021051703.04 in my case)
• now for each plugin folder ( pdfannotaor , moodle overflow , and download centre) open the, and open index.php file
• you will find a line whith " $plugin->requires = 2018051703.04;" if not add this line and the version number here is the number copied in above step.

Now we place the folders in moodle directory

• Open the folder xampp in C:/
• then go to htdocs
• then open moodle ** open mod folder and paste pdf annotator and moodle overflow folder there ** open local folder and paste download centre folder there

now simply open moddle and you will be popped p with the installation of these plugins.After installation you can follow the demo to see their use.