Yes it can. Just use the resize wizard is the easiest way, though I can't remember off hand the precise order of things just now (well past my bedtime). However I don't think you can go far wrong. It is self explanatory really.
PM manual states that you should backup all your data before doing anything. This is absolutely necessary as it is possible for the operation to go wrong, not very likely, but I have had it happen once.
Otherwise, the operation is very easy as the wizard will guide you through it. And no, I don't know of any way you can 'rewind'!