Code samples for the for blog post: http://everydaylifein.net/netframework/modifying-the-project-during-nuget-package-installation-and-removal.html

ChangingBuildAction.ps1

$x86TalkFX = $project.ProjectItems.Item("CroccatTalkWrapper").ProjectItems.Item("win32-x86").ProjectItems.Item("talkfx-c.dll");
$x86TalkFX.Properties.Item("BuildAction").Value = [int]2;

ChangingCopyToOutputDirectory.ps1

$x86TalkFX = $project.ProjectItems.Item("CroccatTalkWrapper").ProjectItems.Item("win32-x86").ProjectItems.Item("talkfx-c.dll");
$x86TalkFX.Properties.Item("CopyToOutputDirectory").Value = [int]2;

NugetPowershellScriptHeader.ps1

param($installPath, $toolsPath, $package, $project)

TestingTheProjectInPackageManagerConsole.ps1

$project = Get-Project [projectname]