How to Delete a WIFI Network on a MacBook From Wifi Menu, open Network Preferences: Click on Advanced... Highlight and delete the network, by clicking the minus (-) sign. Click OK. Search for, and open Keychain Access In Keychain Access, search for the name of the WIFI network. Delete the key that appears. Type in the computer's admin password: Though we hope not to have to go remote, being prepared for this possibility allows for as smooth a transition in teaching and learning for our community.