Hey, if you figure out a way of doing it that's fun and easy, let me know how.
I make and edit gifs with adobe photoshop, image ready and an a program called GIF construction set pro. However, these scenes are actually from gifs I found while lurking around /gif/ on 4chan. Whoever posted them probably made the original gif and I just drew over them frame by frame.
So the answer is; I'm not sure. I suppose finding an episode online, downloading it and using programs to convert it would be one way to do it.
As for making more, I won't be anytime soon. The old computer i did my art on blew up and I'm trying to get around to buying a new one. And I find making these gifs extremely time consuming and boring.
Still, if you fancy making them then go for it, I look forward to seeing some.