To replace brush heads:
Pull firmly to remove existing brush head. Align new brush with the square, tapered end of the turbine shaft and push FIRMLY into place.
Good quality and price with the discount.
Love it but wish I could purchase the stiffest brush (blue) individually, as I don't need the others.....
I had a defective part and the customer service was amazing! Replaced no problems at all. Works well on my Harley