Todor Nikolov writes:
If you work with Rigify you may have wondered if it's possible to edit all of the control shapes that the addon automatically generates for us.
(If you're new to Rigify check out this playlist)
It is possible and it is relatively easy to do. When you generate your rig, Rigify creates a collection called WGT. This collection is hidden by default. Just unhide it and you will have access to the shapes. You can then edit them as any mesh in Blender.
You may encounter some problems and errors in this process. I explain all of them in the video below.