你 need an 动画片 program. I use GIF Construction Set, but there are lots of programs out there. Most of them cost money, though. It's hard to find a good free 动画片 program.
Once 你 have the program, then it's just a matter of making a series of still 图片 (frames) that will look good when animated together. The 动画片 program will do all the work for 你 after that point. 你 just tell the program which 图片 你 want to animate, add some effects (if 你 want to) and the program will combine everything into one animated image for 你 :)
