It's a very complicated and tedious process. Here are the basic steps:
1. Download Beneton Movie GIF
here.
2. Find a video that you want to make the GIF with.
3. Find the part of the video that you want to make your GIF with then pause it.
Make sure that your selection is not too long, or else your GIF will become too big to upload anywhere.
4. Take a screenshot at where you pause the video when you were choosing the part of the video that you want to make your GIF with.
To take a screenshot, press your "prt scr" key which is located next to your scroll lock key. Then, go to Microsoft Paint>Right click>Paste.
Also, remember to crop your screenshot so that we don't see your whole computer screen.
Oh, almost forgot,
always name your series of screenshots "GIFX" with "X" being a number starting from 1.
5. Play the video and then press stop immediately. Then, take a screenshot again. Repeat this process until you are done with your selection.
What you are essentially doing is taking a screenshot of every single frame of the video to the best of your ability.
6. Open your screenshots/frames in Beneton Movie GIF.
7. Set the time delay in between the frames.
If you need any more help, feel free to ask.
By the way, I made this not too long ago, sadly, the file size is too big to make it my signature here:
You can tell where I got my idea from...the "Elvis on Tour" trailer.