Adding and Removing dll's from the GAC using Powershell

To add a .dll to the GAC

Run the SharePoint PowerShell console as Administrator

type : Set-location <path to dll's here>

[System.Reflection.Assembly]::Load("System.EnterpriseServices, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")

$publish = New-Object System.EnterpriseServices.Internal.Publish

$publish.GacInstall( <path>\RandomcodemonkeyDLL.dll)

 
To remove a .dll from the GAC

$publish.GacRemove( <path>\RandomcodemonkeyDLL.dll)

A good way of getting the names of you assemblies from  :
 Simplest way to get the strong name of an assembly
http://nileshmandekar.blogspot.co.uk/2012/03/simplest-way-to-get-strong-name-of.html


A very elegant way of getting the dll's in and out via script is like this from Fred :
http://fredericloud.com/2011/01/08/no-gacutil-no-problem/