Note: These instructions apply only for PDFs opened through Google Drive. For the Texthelp PDF Reader to not open PDFs from websites please read How can I disable PDFs opening with the PDF Reader from websites.
To have PDFs to open in Preview instead of the Read&Write for Google Chrome PDF Reader, go to Google Drive and click the Settings button
In the Settings menu, select Settings
In Settings choose Manage Apps
In Manage Apps locate Read&Write for Google Chrome™, Texthelp PDF Reader (and if you also have Read&Write for Google Chrome™ Legacy) untick Use by default
Note: Read&Write for Google Chrome can still be used with this option selected
PDFs will now open with Preview by default. PDFs can then be opened with the PDF Reader by using the Open with option in Preview