Most folks replace the entire wiper blade.
There is no need to worry about potential performance problems caused if the refill doesn't fit properly or the blade frame is damaged. Installing a brand new wiper blade also gives your windshield a fresh look. For those who choose wiper refills, it's a little more technical. You will need to know if the wiper blade you are refilling came with the car new or whether it's been replaced already. If it has been replaced, you'll need to know the brand and type of blade for accurate refill parts.