If you’d like to disconnect an instance of a Custom Page Part from its Custom Page Part, you can. This will make the Custom Page Part be simply a matrix Page Part with the same configuration.
1. Find the page part on /admin/pageparts
2. Select the name of the page part to edit it
3. Select the *Disconnect* tab
4. Select the button that reads *Yes, I understand and would like to disconnect this custom page part.*
Note: this may take some time.