To replace brush heads:
Pull firmly to remove existing brush head. Align new brush with square, tapered end of turbine shaft and push FIRMLY into place.
Just used my Brush Hero to clean some mildew off my vinyl siding. Worked great on those shady areas where I get mildew build-up.
I have replaced the brush one time thus far--easy to assemble/install.
Glad I bought it
Just used it for the first time. Actually kind of amazing. Four little spray jets come out the end straight into the brush, which is also spinning b/c of water jets. So for bikes, this is perfect--no direct spray is hitting your hubs or headset. Super quick cleaning of those hubs as well, in between the spokes, along the rim, etc. Personally, I'd like to see some kind of soap dispenser attachment, but this thing is so surprisingly useful, I'll stop my quibbling there. Looks to be very well made and will stand up to some abuse.