You mean like mine? Well first you have to get a toaster. Put mayonnaise in it. Spin in a circle 3x, and then jump in the air and say "I'm your bitch Acro." That is how you do it.
Ok I will tell you how to actually do it. You need to find a GIF you like, and it has to be the correct dimensions that FK has given, or roughly close. I just saved mine on my desktop, uploaded it, and it worked. Hope you get it working. If not PM me, and I'll see if I can help