Better instructions for using preview SDK's from Visual Studio #8969

I wanted to test out some of the Span functionality, so I was attempting to install the newest preview SDK in order to do this. I installed the latest version of the preview SDK (2.2.0-preview1-007851 at the time of this issue), and made sure I was using Visual Studio 15.5.2. I also added the myget nuget package source to my solution. However, visual studio does not seem to properly be restoring everything. I get an error Unable to find package Microsoft.NETCore.App with version (>= 2.2.0-preview1-007851), and then a whole bunch of errors saying the System namespace can not be found. I can't find any more instructions on how to make it easy to use preview SDK's from visual studios. Can I get some help with getting this working, and potentially some better instructions for future users who want to do this? Below I have put my csproj file.

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.0</TargetFramework>
    <RuntimeFrameworkVersion>2.2.0-preview1-007851</RuntimeFrameworkVersion>
    <LangVersion>7.2</LangVersion>
  </PropertyGroup>
  
</Project>