refinishing hardwood floors that have particle board over them

I bought a house that has hardwood floors throughout but the previous owner used ring nails and put particle board over the top of it as a subfloor and laid carpet. What is the best way to take up the particle board with as little damage to the hardwood floor as possible? I am doing all the work myself (family members know how to do it but won't help) and I really don't know what I'm doing.