Well, if you have ordered potting medium from repotme, then I am surprised that you missed this video:
Orchid Care Video - Repotting a Phalaenopsis
This is pretty much how I do it.
There is a thread at the top of the beginner forum that is called "The Phal Abuse Ends Here" read the first 12 pages or so of this thread. The advice here is so worth the time it will take you to read it. Phals can be quite tough, even though they are the most commonly available orchid, don't feel bad if you kill this one. I've killed several phals in my time. It took me a while to find some hybrids that grow well for me in my conditions.