Setting up myPWS is very easy. All you need is a

• Station ID, and an
• API Key

A Station ID is a unique ID of a PWS (Personal Weather Station) registered on Wunderground.com, an API Key is a key that gives you access to the readings sent by your weather station to Wunderground.com.

You can find both in your Wunderground Account, which you can access through this link. When you start myPWS for the first time, you will be asked for a Station ID and your API key. After entering both into myPWS, myPWS will connect to the Wunderground.com server. Then you have full access to myPWS.