Road film tends to build up on the wiper blades thus reducing their effectiveness, washing with diluted mild detergent will help in this respect. The windshield wiper and blade assembly should be checked from time to time because the rubber that is used is likely to dry up due to constant exposure to sun and this will result to cracking and breaking. If the rubber is not smooth to the touch and the feel of it is hard or cracked, then it has to be replaced. If it is clean, spray the windshield, switch on the wipers to run several times and turn off the wipers; If the pattern on the glass is uneven or streaked, then it is high time to replace the blades. Blade may wobble due to the action of wiper mechanism that is controlling it hence loosening of fasteners is commonplace; it is during blade removing that fasteners should be checked and tightened if necessary. In as much as wipers are replaced, park them in right position through engaging the wipers and switching off the engine when they are in the right position. Hold the blade by the top and raised it a little bit from the windshield, at the same time press the retaining lever then the wiper arm can be pulled out of the blade, after that one needs to remove the blade while taking care not to twist the spring lock. Place the new blade as far as it can go on the wiper arm hook and when it cannot go any further, it is locked in place. For wiper element replacement, take a flat head screwdriver that should be used to free the wiper blade by applying pressure on the blade as you turn the screwdriver to the clockwise direction, the retaining claw should let go of the element. Slide the element out of the remaining claws, and then to replace a given element: take either end, place an element into the second retaining claw and move all the way to the end. Lastly, put the element back into the claw of the blade bending it as it comes to the end of the blade.