Make sure you have closed the project that you are updating before following this guide.

First update Player Build System in the Epic launcher and create a new Player Build System project. Then go to the new projects files in windows explorer and copy BP_BuildMaster file found in the folder:

PlayerBuildingSystem\Blueprints\BuildingBlueprints\BuildTypes

Then go to you projects files to the same location listed above and paste the BP_BuildMaster and replace the current one you have.

Next go back to the new project you created and copy the PlayerBuildingComponent file found in the folder:

PlayerBuildingSystem\Blueprints\Components

Then go to the same folder in your project and paste the file replacing your current version of the file.