As above,, not sure if you know or not... there are two pieces to that floor tool.
The elbow part separates from the wide floor part by squeezing the two little buttons on either side just in front of where it says "this side up" Squeeze to two buttons and Pull the two apart then turn the wide brush part upside down and reinsert to use the other side of the tool
As it shows in the pic above it's set to use the gleaner side so if you want to use the brush side,, do above.