The installer may place a new RealCADD Lib folder and a new Scripts folder in Documents >> RealCADD. You can check this by opening RealCADD and looking to see if your Library now contains new demo files, or is as it originally was.
If the Library has been replaced, navigate to Documents >> RealCADD, trash the new Library and Scripts folders and drag your copy original Library and Scripts into the RealCADD folder.
Depending on your system setup you may be asked to authenticate the move by entering your Administrator name and password. Also, depending on your system setup, simply dragging may create an Alias rather than a Copy. Holding down the ⌥ (Option) key while dragging will force a Copy.