Hi,
first option I can see is to use the same project. Just don't turn the Z0 on, move all the required code to Z6, adjust the linker file if necessary (you don't need to allocate a lot of space in RAM and flash in Z0 now).
Second option is to create new project for single core only (not sure which IDE you use), so you will save some memory occupied by startup code for Z0, by interrupt/exception vector tables for Z0 and so on... The linker file will be optimized for single core in this case. Copy all the code to new project, add the code originally written for Z0...
Not sure what else we can suggest because that's too general question...
Regards,
Lukas
