1. unpack the zip file.
2. read the extracted file manual.chm - section "How to Use"
3. in manual.chm - section "Core API" read about the functions of interest to uou.
How to Use
Put WinRing0.dll, WinRing0x64.dll, WinRing0.sys, WinRing0x64.sys, and WinRing0.vxd
into the directory where your application's executable file resides.
Visual C++ 2005/2008
See also sample application.
Load-Time Dynamic Linking
Add WinRing0.lib or WinRing0x64.lib to your project.
Add #include "OlsApi.h" statement to your source file.
Call the library's functions.
eg. ReadIoPortWord, WriteIoPortWord