For Blueprint in the content, right clic on it, migrate.
For source code, you can:
Simple Way
Copy past the directory inside [Source/YourOldProject], add YourOldProject to Source/YourNewProject.Target > ExtraModuleName.AddRange && to YourNewProject.uproject add
“Modules”: [
{
“Name”: “YourOldProject”,
“Type”: “Runtime”,
“LoadingPhase”: “Default”
}
Don’t forget IMPLEMENT_PRIMARY_GAME_MODULE that become IMPLEMENT_GAME_MODULE
Fully Integrated Way
Copy your source into your new project source folder. inside theses .h sources, rename YOUROLDPROJECT_API to YOURNEWPROJECT_API.
If your blueprint reference to theses source, add inside Config/DefaultEngine.ini
+ActiveGameNameRedirects=(OldGameName=”/Script/OldName”, NewGameName=”/Script/NewName”)
+ActiveGameNameRedirects=(OldGameName=”/Script/YourOldProject.OldSource”, NewGameName=”/Script/YourNewProject.OldSource”)