[71GMC_3/4T]

Like Zurbo said, press on the little tangs to release the pins and pull them out the back. Be sure to make a list of how it was connected so you can get it back the same. Also, before you reinsert the pins, lightly pry out on the little tangs so they will click back in the connector shell when you put it back together.
I had to pull mine apart when I redid it too. Use the old wires to pull in a scrap wire as a "pull string" to use to pull the new one in place.
Also, if your new switch has the arc shaped connector and you want to switch to the straight one for your truck, you can insert the pins into whichever connector you want to use, provided you get all the colors right.