First, head to the default ReMask 5 install directory, and find the folder where your plugin file resides:
32bit Photoshop - C:\Program Files\Topaz Labs\Topaz ReMask 5\PS_Plugins\
64bit Photoshop - C:\Program Files\Topaz Labs\Topaz ReMask 5\PS_Plugins_x64\
Copy the preset file. In this example, we are using the 64bit plugin, so we will copy tlremask5ps_x64.8bf and TopazReMaskAutomation.8li.
Navigate to your Photoshop Plug-ins folder. Then, create a new folder named TopazRemask5. Please see the version you're using below for the correct folder:
Photoshop CC 2015.5 - C:\Program Files\Common Files\Adobe\Plug-ins\CC\
Photoshop CC 2015 - C:\Program Files\Adobe\Adobe Photoshop CC 2015\Plug-ins\
Photoshop CC 2014 - C:\Program Files\Adobe\Adobe Photoshop CC 2014\Plug-ins\
Photoshop CC (2013) - C:\Program Files\Adobe\Adobe Photoshop CC\Plug-ins\
Paste the tlremask5ps_x64.8bf and TopazRemaskAutomation.8li files into the Plug-ins folder.
If you are prompted, confirm that you want to paste the file by pressing the Continue button. Start Photoshop, and get to editing!