I had the same problem i just used a g-clamp to push the piston in and at the same time used a pair of grips to turn it clockwise. Be careful not to damage the rubber boot around the piston as this is a dust guard. Take a look at the following links

http://www.gwfweb.com/01accord/19-19.jpg

http://www.gwfweb.com/01accord/19-20.jpg