The role the user is assigned to dictates what permissions and access the user has, to move a user to another role for the same site you must first detach the user from the existing role.
By role
Click Admin Cogs along the top bar.
Click Organisation Administration, then click Roles.
Locate the role and click Edit to access.
Click the Associated Users tab.
Locate the user you wish to detach and click the Chain.
By user
Click Admin Cogs along the top bar.
Click Organisation Administration, then click Users.
Locate the user and click Edit to access.
Click the Associated Sites tab.
Locate the site and click the Chain, the red cross will delete any connections associated with this user with the site such as mini markets and departments.
By site
Click Admin Cogs along the top bar.
Click Organisation Administration, then click Sites.
Locate the site and click Edit to access.
Click the Associated Users tab.
Locate the user and click the Chain, the red cross will delete any connections associated with this user with the site such as mini markets and departments.