Choose the free select tool (lasso) or another select tool
Select the parts you want to make moving in the gif (surround these parts and close the line by clicking in the dot)
and copy these parts
Paste the parts and (this will be an extra layer)
Move these pasted parts a bit
(press m to make the pasted bit, the layer, movable if needed)
In Layer choose an option to include the layer into the picture. (merge down)Save every changed image.
Name and number the saved images. Like image1; image2 etc.
(the gif will use the numbers )
Export as gif (give the image a name with extension .gif. In order to make Gimp know you want to export as gif. )
Activate the option “animation ”
Experiment and try all options.
You want to improve this how to and add your comments.
You are encouraged to copy this how to and to improve it and publish it. (I would like to receive a comment if you do reuse and improve my how to.)