Externals are easy. Pull the slide off , turn it over, punch the roll pin out the top.
You don't have to punch it all the way out unless you are replacing it as well.
A new roll pin is a b##ch to get started sometimes.
Be sure to capture the spring at the back of the extractor. A turn of tape to secure the extractor is what I use to keep it together.
Make sure you have a good pin punch of the right size, and a soft hammer to put the pin back down. Sorry I don't remember the pin punch size.
Hope this helps. goldy