Try this:
Create a folder under your C drive named: VSTPlugins
Unzip the files and specify the extraction folder as C:\VSTPlugins
All unzip programs allow you to choose the folder where you want to extract the files. Select C:\VSTPlugins and extract the files.
Open Reaper and the Preferences menu and click on the "Add" button. Add C:\VSTPlugins to the list of directories.
Click on the "Rescan directory" and see if the plugins are now available for use.