When you need to update membership fees:
Organization fees
Organization fees are in civicrm. Administer > Civi Contribute > Manage Price Sets. You get to the same place through Administer > Civi Membership > Manage Price Sets.
There is one item in the list (Organization membership). Select the link "View and edit price fields".
Note that the two Sustaining price fields are disabled. Enable them here to allow sustainers to use the organization membership registration.
For the operating budget, select "Edit price options"
Edit existing options, disable, or add new options. You can edit the label or the amount for any existing option.
Individual membership fee
Administer > Civi Member > Membership Types
For the "Individual Pillar Membership", hit the edit link (on the end of the row).
You can change the minimum fee, and the name. Do not change anything else on this page.
Adding messages about service fees
There is another page of help with instructions for changing the messages. I've added instructions about service charges to that page.