Update Mvc application from 4 to 5

Make sure you have back up of your project before you start updating your project.

Open Manage Nuget Package for the solution
Update Entity Framework
Update Asp.Net Mvc
Update Asp.Net Mvc web api2
Installed Microsoft.AspNet.WebHelpers

The idea is to update only top level package and it automatically updated other packages on which these packages were dependent on.

Update web.config
<add key="webpages:Version" value="3.0.0.0" />

And Update web.config in views folder for mvc version to 5

Compile your project and you should be ready to go at least I was able to update my project following these steps.