Do you need to edit the role of a member in your community who is in Invited state, before they accept the invite? Follow these steps - 

1. Click on the name of the community in the left navigation tray
2. Click Members
3. Click to expand Invited section
4. Click on the name of the member whose role needs to be changed
5. Click Options in the top right corner of the Profile screen of that member
6. Click Edit Role
7. Click Role Type
8. Select the Role you want 
9. Click Save

Note: The role of the invited member is now changed. When he/she accepts the invite, they will be joining as the new role.