Well before you go at this, have you tested various things or are you guessing?
check your fuses
Check for a blown fusible link (wire off battery running along fender, fusible link usually in that wire).
Check for bad headlight relay with test light
If both fuses okay, and relay is putting out current (or you can doa substitute with another relay in the relay box if they have the SAME part number exactly) check with test light if you are getting current to the headlight socket
If no current to headlights and all fuses and relays are known to be good, then come back here and we'll talk about switch replacement.