Photoshop is an incredibly powerful tool that is capable of doing many things, but the trick is figuring out how to get it to do what it does. Editing an animated GIF in Photoshop is easy... when you know the steps to take. With these steps you can edit an animated GIF using Photoshop on a Mac or a PC.
To open an animated .gif on mac, click open, select your GIF, then in the bottom left corner of the open file dialogue box select Quicktime Movie as the format, then open your GIF.
You'll need to open your animations window by going to window then clicking on "animation". This will bring up a time line that you'll have to get familiar with.
If you want to have all of the frames broken up into layers, click the options in the animation window, and select Flatten Frames into Layers. This will give you access to all the frames as layers and you can now edit the GIF as though it was a movie.
In my case, I didn't need the last step. I had an animated GIF where the animation was perfect. I just wanted to edit the static parts of the GIF. So rather than editing each frame or the layer for each frame, I created a new layer on top of them all and entered the new logo.