ZAP Z-7 Debonder ensures that super glue, super glue or superglue (also called Cyanoacrylate) softens and sometimes dissolves. With this you can release glued parts such as your thumbnails (or your fingers).
Apply in a generous amount and let it work for a few minutes. The glued parts will then come apart relatively easily. Depending on the glued surface.
The Debonder is odorless and will not stress most plastics. The remaining glue will become hard and can be scraped off the model with a knife.