If you would like to change the permission role of a user, you can select another existing role for this the user.
Be advised that changing a user's role might have impact on the user's Q&A.
Step 1: Navigate to Roles & users;
Step 2: Select the user(s) you would like to change;
Step 3: Select Change role;
Step 4: Select the new role from the drop-down menu and select Save.
Note: A user can't be moved from a role on the question side to a role on the answer side, or vice versa.