Replacing an animated image with another

Hi, I have complicated character which is animated by rotating layers. I want to change its some parts (drawn by gimp so it is png) with another. Since I have complicated grouped layers and have more than 10 png images I don’t want to drag and drop and try to figure out which part is belong to which group. Since gimp exported .sifz files have a directory full of png images I thought there may be a way to re-read those images after some changes or I can just replace the png layers with the same named ones automatically. So is there anyway to achieve this?

p.s. I’m using Linux

I have the same problem. I animate tears, and would like to change the look of it, and import new layer, in the place of the old one - keeping animation intact. Have you managed to find solution?