Installing Hardwood Floor, How Do I Handle The Particle Board Subfloor?

I am installing 3 / 4 "hardwood floors. My subfloor is particle board and not be used for installation of wood. I put a new plywood subfloor in the particle board but work under the walls, and can not be completely removed. I Stop the beam closest to the wall. Are there any recommendations on a overlayment plywood, or a procedure to replace the basement?