Visual Studio 2010 editions - switching from Premium (not a trial) to Ultimate trial and back again

I have installed Visual Studio 2010 Premium RTM (not a trial) and would like to run the Visual Studio 2010 Ultimate Trial for a while.

What is the fastest way开发者_C百科 to switch to Ultimate trial and back again to the Premium?

My best idea:

1. not uninstalling the Premium edition.
2. running the Microsoft Visual Studio 2010 Ultimate Trial - Web Install
3. testing the Ultimate trial
4. uninstalling the Ultimate trial
5. repairing the Premium installation

Probably the safest way would be to run the trial in a VM under VMWare or VirtualBox. I wouldn't trust different versions or levels of the same software to run nicely together.

But I'm inherently paranoid :-)