When the wipers no longer clean well, the blades are probably worn or cracked. Replace them.
CAUTION
To prevent damage to the wiper arms and other components, do not try to sweep the wiper arm by hand.
NOTE
When raising both windshield wiper arms, raise the driver's side wiper arm first. When lowering the wiper arms, slowly lower the wiper arm from the passenger's side first while supporting it with your hand. Forcefully lowering the wiper arms could damage the wiper arm and blade, and may scratch or crack the windshield.
1. Raise the wiper arm.
2. Open the clip and slide the blade assembly in the direction of the arrow.

3. Tilt the blade assembly and remove it from the arm.

CAUTION
To prevent damage to the windshield let the wiper arm down easily, do not let it slap down on the windshield.
4. Pull down the blade rubber and slide it out of blade holder.

5. Remove the metal stiffeners from each blade rubber and install them in the new blade.

CAUTION
So do not use the driver's side metal stiffeners on the passenger's side, or vice versa.
6. Carefully insert the new blade rubber. Then install the blade assembly in the reverse order of removal.

Wiper Blades
BatteryMazda 6 Owners Manual: Fuel tank inspection
Caution
Disconnecting/connecting the quick release connector without
cleaning it may possibly cause damage to the fuel pipe and quick release
connector. Always clean the quick release connector joint area before
disconnecting/connecting using a cloth or soft brush, and make sure that it ...
Mazda 6 Owners Manual: Shift-Lock Override
If the selector lever will not move from P using the proper shift procedure,
continue to hold down the brake pedal.
1. Remove the shift-lock override cover using a cloth-wrapped flat head screwdriver.
2. Insert a screwdriver and push it down.
3. Press and hold the lock-release button.
4. Mov ...