Simply release the bearing strip and the entire thing slides out.
Again there are little raised tabs that are accessible with slots in the sideframe. You gently- keyword there, press in on that tab while at the same time carefully lifting the wheels to slide the bearing strip one axle at a time up to the unlocked position. Once all 3 are unlocked, then you can lift the strip and axles as a unit.
In that photo you can see the plastic bearing strip is able to slide back out. I just do not have a picture of the slot where the locking tab protrudes.