Upgrading complex c++ UE4 project to UE5

Hi all,

I have a complex c++ UE4 project that I would like to migrate to UE5.
I’m hesitating between 2 techniques, one brutal, the other gently.
The former I would have thought of copying all the c++ files and blueprints and pasting them into the UE5 project then debugging gradually. The next one is to open UE4 and UE5 simultaneously (is it possible?) and copy paste all my C++ files but copy only one blueprint at a time, debug, compile, and once it works, move on to the next blueprint and so one until all my blueprints are compiled successfuly

What technique do you recommend please?