There is a spanner grip to the end of the shaft which it is worth trying to at least turn the shaft before pressing it out. If you use a hammer and drift to knock it out, chances are you're going to damage the thread and flare the end. With the price of porta power sets these days it is a must to have one in you're workshop.
I have used a couple of 20mm threaded rods and plates to hold my guide in place. One thing you do need to do and thats use a strong clamp to keep the support arms together. If you don't do this you will end up spreading them apart and dissaligning the shaft and believe me it just will not come out. I have got it down to about 12-15mins per wheel with this method. It may not suite everyone but it sure works for me.
Oh! and thats my 6 Year Old

Andrew, I'm just grooming him for future lifting, cleaning, welding, cutting, grinding and making coffee

Colin.