The installation process of the Product Page Pack Template is the same As other templates from seb de la web.
You just need to Download the XML file and then import them from WordPress Importer . It will import as UX blocks.
After Importing the XML file you will see the CSS code for the Product Page Pack You just need to grab them and Paste them to the Flatsome / Advanced / Custom CSS / All Screen.
After that, to set your Awesome Custom Product Page as a Product Page Layout you need to go to Flatsome / Theme Options / WooCommerce / Product Page
You will see a Section called Layout,
Then select Custom then you will see Custom Product Layout and you can select Product Page 01 to 07.
Select the one you like and you are Good to Go.
If you face any issues during the installation contact me I will help you to go through it.