here is one possibility to do this:
You could save a copy of the project via the menue "Project > Backup project".
After opening the backup copy of the project you can delete all codes, for example by choosing "Codes > Frequency of codes", marking all codes, right click and choosing "Delete Code".
Create a new code named "New perspective" or similar. Recode your data with a new code system, which you build up under this code.
After you finish the coding with this new code system, you can use the function "Project > Merge projects" to import the old codes and the coding work into the new project.
We recommend that you backup your projects before you merge them, because you can't undo this procedure.
MAXQDA Support Manager, stefan DOT raediker AT maxqda.de