Disable inheritance from parent

Question

Where i disable inheritance from parent. I want delete several groups. Where i delete this groups

Where i disable inheritance and add users from root site -> user goes in sites where this group existing ?

Answer 1

If I understand your question properly then,

If you click Delete Unique permissions, then all the permissions you've set uniquely will be deleted.

After breaking the inheritance, if you want to remove the groups then select the names of the groups/users and click Remove User permissions. The group/users (you delete here) will not be deleted but their permissions from particular site/list will be deleted.

If you want to add users/groups then click Grant Permissions and add users/groups and set desired permissions.