Help with plugin not compatible with WooCommerce HPOS (original) (raw)

• I am using a simple plugin to provide quantity increase and decrease buttons in WooCommerce. However, it is stated that it is not compatible with HPOS. The plugin is not updated anymore but it is the only one I can get to work on my Theme. Is there a way to manually change the code to make it compatible?
  I tried several other solutions without any luck. I have even tried to turn the plugin into a code snippet.
  This is the plugin in question: Qty Increment Buttons for WooCommerce – WordPress plugin | WordPress.org