How can i edit a group permissions

[Mahesh S]

Please refer this document for your question. It gives a detailed view and helps further learning.

https://confluence.atlassian.com/jira/managing-project-permissions-185729636.html

[Nic Brough -Adaptavist-]

You edit the permissions and include or remove groups in them

Ideally though, you edit the permissions, and only use roles in them.  Then you can do the groups by adding/removing them in project roles.