Intro

<yes, I know, more text to come>

Credits

- MSDN Blogs > syamp's musings > How to run FIM 2010 PowerShell Cmdlets from a remote machine?
- Installing FIMAutomation on a FIM-less machine
- FIM 2010 – Registering FIMAutomation class on another system

Get the FIM libraries

From the %program files%\Microsoft Forefront Identity Manager\2010\Service folder on the FIM server, copy the following files:

Microsoft.ResourceManagement.Automation.dll
Microsoft.IdentityManagement.Logging.dll
Microsoft.ResourceManagement.dll

Copy the FIM binaries to a local drive.

Check the target machine OS version

The location of the utility we will used depends on the OS you're running.
On a 64-bit machine, InstallUtil, resides at

C:\Windows\Microsoft.NET\Framework64\v2.0.50727\InstallUtil.exe

While the 32-bit defaults to:

C:\Windows\Microsoft.NET\Framework\v2.0.50727\

Use the right tool version

As suggested by Brad Turner (here)

x64

set-alias installutil $env:windir\Microsoft.NET\Framework64\v2.0.50727\installutil

installutil .\Microsoft.ResourceManagement.Automation.dll

x86

set-alias installutil $env:windir\Microsoft.NET\Framework\v2.0.50727\installutil

installutil .\Microsoft.ResourceManagement.Automation.dll

Register the FIM libraries

(1) > InstallUtil.exe -i .\Microsoft.ResourceManagement.Automation.dll
(2) > gacutil -i Microsoft.ResourceManagement.dll
(3) > gacutil -i Microsoft.ResourceManagement.Logging.dll

Load the pssnap-in

From the Powershell command console execute this command to load the snapin:
add-pssnapin FIMAutomation

You will see that lots of scripts load the snap-in during executing, like

If(@(get-pssnapin | where-object {$_.Name -eq "FIMAutomation"} ).count -eq 0) {add-pssnapin FIMAutomation}

Run Powershell with remote URI

In your FIM powershell scripts you need to define the URI, which refers to the FIM Service.
When you run powershell scripts from the FIM Service machine, the URI is set to local host, like

http://technet.microsoft.com/en-us/library/ff720152(v=ws.10).aspx

But when you run the powershell remotely, you'll need to change that localhost to the remote FIM Service machine name.
<text>
In lots of scripts this setting is defined as a variable in the beginning of the script, like

set-variable -name URI -value http://localhost:5725/ -option constant

Hints & Tips

Brad:
If you attempt this from a mapped drive you will receive the following error:

Exception occurred while initializing the installation:
System.IO.FileLoadException: Could not load file or assembly 'Microsoft.ResourceManagement.Automation, Version=4.0.2592.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417).