AC pressure switch tripped / failed?
I can tell you now that the condenser should be cleaned but I guess that's off topic.  If you are confident about the switch then most likely you will have to reclaim the refrigerant, replace the switch, pull vacuum and replace refrigerant.  Minimum items needed, Reclaiming pump, Reclaim cylinder, vacuum pump, gauge set, etc.  You'll need a service tech for this one.  If you do bypass it, clean the condenser because because that can cause an elevated head pressure.