Are your windshield wipers leaving streaks?  Probably time to change them.  The manual says to inspect the wiper blades at least twice a year for wear or cracking.  If it looks like the blades need replacement, do it.  Refills are inexpensive and worn blades reduce visiability.  If the rubber actually comes off, you risk scratching your windshield.

You will need 22 inch windshield wiper blades.  If you are going to replace the whole blade, you will need the Shepherd's Hook style.  It is a standard wiper frame, so if you are just going to replace the blades, the standard refills will work.

To remove the wiper blades, you will need to get them out of the parked position.  Turn your ignition key to ON and turn on your wipers.  Turn off your ignition when the blades are in the up position.
I recommend that you place a towel on the windshield.  This reduces the risk of scratching the glass with the wiper or wiper arm.  You might also accidently release the arm and the spring will snap it against the glass.  A thick towel will help guard against cracking the windshield if this happens.
Lift the arm away from the glass.  There is a release clip under the blade connecting point. Press this clip and pull down the blade assembly toward the arm
This is the release clip.  This blade was already removed from the arm for this photo.
Word of warning.  Depending on how far you let the wiper arm travel before turning the ignition off, lifting the arm may cause it to touch the trailing edge of the hood.  Be aware of this as you could chip the paint off the hood.
This is what it looks like when the release clip is disengaged and the blade is pulled down along the arm.  It is a little tricky to remove the wiper.  You have to pull the wiper down to clear the hook, then thread the hook out of the frame.
This is the end of the arm after you remove the blade.  
If you are planning on replacing the whole assembly, just snap the new one on.  If you are just going to replace the blades, you will have to remove the old ones.  On the bottom end of the wiper you will see a retaining tab.  Squeeze on both sides and pull it out.  A pair of pliers may help out here.  This is a photo of the blade after it was removed.  Now just slide the new ones back in.  The factory wipers are rubber with stainless steel inserts in the sides.  These are a real pain to install because you have to keep the inserts in while attempting to thread the refill into the frame.  Other manufacturers may have different approaches.  In any case, the refills should slide neatly into place.  The refills I got were a tiny bit too wide.  They would fit, but I had to really work to get it into place.  I just shaved a little off each side and it worked nicely.  There should be some sort of locking mechanism to keep the refill in place, just follow the instructions on the package  Now just reinstall the assembly.  Make sure it snaps into place, you don't want it coming off when you are on the freeway during a storm.

Do not attempt to replace the blades with the frame still attached to the wiper arm.  It's not easy to remove the blade and you will damage something.

Like I mentioned, pretty much any standard size refill will work.  I purchased a set of TripleEdge refills from a local store.  They are made from silicone and are not supposed to tear, crack, split, etc.  It also leaves a silicone shield on the glass that makes water bead and roll off.  What the heck, it was only $6.  They have a lifetime warranty so if they fail, you can request a replacement pair.  You need to send them $3 for shipping and handling and they will send you a replacement set.  It says that it will take 2-3 weeks.  I think I would just buy another set vice wait that long.  Which is probably what they are counting on.  In any case, they work ok so I'm happy.