Yep, my grandfather used to rope me into helping him with de-spur his roos all the time when I was young. He used the potato method, and I personally think it's one of the better ways to do it as it doesn't bleed like other methods may cause, and the birds seem to not be in any pain during the procedure.
Here's a really good step by step guide:
http://www.ehow.com/how_8156470_trim-roosters-spurs.html
The only thing I would add to the guide is a couple of items to make your life easier:
1,) wrap your rooster in a towel, such that it covers his eyes (leave room for him to breathe though), and has his legs sticking out. This will keep him from struggling from being held too long.
2.) Make sure your potato does not touch the rooster's leg, just the spur. You can wrap the leg in a seperate towell, with spur exposed, if you want to be extra sure you don't accidentally burn the leg.