--> I thought I want to study how to remove the software. <--
Here is some stuff to read about it.https://forum.porteus.org/viewtopic.php?f=39&t=1473https://forum.porteus.org/viewtopic.php?f=39&t=5116https://forum.porteus.org/viewtopic.php?f=81&t=5070
If you are saving changes, you can delete (whiteout) software with the pkgtool.
This will not delete the software in the original modules.
open a terminal > su to root and type pkgtool
But before you delete something,Make a backup of your "changes" so that you can go back to the previous stage.
something might go wrong....better safe than sorry...