How to move CPP classes (BP function library, actor) into a newly created plugin?

Hi, I made some CPP classes to help me spawn some stuff on splines and I want to move them into a plugin so I can copy paste it into another project.
How do I move the classes to a plugin? Do I need to modify C++ code?
I tried moving it simply in the content browser but it doesn’t let me, even though I have “can contain content” checked.
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Thanks for any tips!

Solution : move .h .cpp files to Public and Private folders inside plugin folder and change some code