Remove the nuts that hold the end caps in place and then wrestle the brush strips out and the new ones into place. It's tougher than it sounds. The final challenge is getting the nuts properly re-tightened without over-tightening them. I got frustrated with that detail to the point that I just replaced the whole brush roll with a VibraGroomer II. It seems like a torque wrench might be handy for that, if one knew what setting to put it on.