I need to work on a Windows 10 specific driver type. Getting and installing the WDK 10.0.10075 is no problem. I had Visual Studio 2013 Pro installed prior to installing the WDK.
The online samples should be for VS 2015 RC. A lot of the samples have even been converted to be universal driver samples.
For kernel mode drivers, it should be possible by moving various MSBuild files and editing some of them, which is similar to what you tried to do. Note that this is not officially supported in any way. For user mode drivers, it is very unlikely that it will work. The Windows 10 WDK has a dependency on the matching SDK version, and because of all the changes that were made to support universal apps and drivers development, the SDK is tightly coupled with VS 2015.
In the MSBuild toolset, there are also a bunch of properties that are assumed to be defined, and some of those will only be defined if you are using VS 2015.
Note that your SDK and WDK versions must match. SDK 10.0.10069 does not match WDK version 10.0.10075.