RAM Useage Reduction - Best Way?

You can make this whole RAM usage reduction process quite safe by making a system backup before you start, not the Windows system restore, but a real backup image of your system drive. Once that's done, it doesn't matter if something you change makes your system unusable. Getting back to where you started from is easy.

Sully''s recommendation of pserv combined with ERUNT for backing up the registry make it easy to undo service and registry changes.

It's a very simple rule that most people don't follow:
If you're unsure what effects the changes you want to make will have (and we've all been there at one time or another) just make sure that you have a reliable way to undo those changes. Once that's done, there's no risk and no reason not to try. System backups do much more than getting rid of malware and unwanted installs. They make excellent reference points when making changes.