the visor squeak is one of the easier ones to work on. if you remove the 2 screws that hold each sun visor on, the whole windshield trim comes right off. Theres a ton of open space and plastic on metal contact; stuff as much open space as possible with felt (just rolls of felt from a fabric store, doesn't have to be stick on) and use 3M anti squeak tape anywhere the plastic touches the metal.
https://www.amazon.com/9325-PTFE-UHM...3M+squeak+tape