I'm finding that while this is a simple thing to do (for us experienced folks), is not so easy to explain!

I'll give you several links so you can read up on what you may not know about this...

Drier...
Three important functions of the receiver/drier in your car’s A/C system | Mobile Air Conditioning Society (MACS) Worldwide

Your Car's Air Conditioning Components

https://www.youtube.com/watch?v=KmpybbtxQmM

How A/C systems work...
https://www.youtube.com/watch?v=w17DpGCcRj8

Pressure switches...
https://www.youtube.com/watch?v=13HcuJ3030g

A/C Pressures...
https://www.youtube.com/watch?v=i9yv0euT7xA

How electrical switches work...
Basic Electricity Tutorial - Switches

Then "short" means to bypass the electrical pressure switch. This would be done by making an electrical connection between the wires going to the switch. BUT BE DARN SURE YOU KNOW THE CORRECT WIRES AND KNOW THEY GO TO A SWITCH AND IT IS THE CORRECT SWITCH!