One possibility is to save, then open again the current image with OSProcess, lastly close the first image. This would work for sure.

The code would look like:�

Smalltalk snapshot: true andQuit: false.

OSProcess executeInCommandLine: './pharo myImage.image'.

Smalltalk snapshot: false andQuit: true.

I do not remember how OSProcess works. I also do not remember how to get the path of the current image and VM to generate the proper command line instruction... But it should work.