How do you replace the windshield wiper inserts??

I think that's overkill. For one thing, will the replacement blade be aftermarket, unknown quality and compatibility? And it seems irresponsible, contributing to mounting waste and landfills, when only the rubber inserts need replacement.

And even that is debatable: I've found cleaning the windshield glass often solved issues, stopped me from replacing perfectly serviceable rubber inserts.

 

Just replaced mine and found the hump end was up on passenger side and down on driver's side. I was confused also but decided to keep the inserts in that orientation until I can check how they are oriented on a new-from-factory Prius.

 

The wiper blade should form a "U" on the driver's side and an upside-down "U" on the passenger side. Hence, "vice-versa" from your description.

You ask why they should not be the same on both sides. Good question. My advice is based upon the Toyota instructions provided with the wiper refills that are packaged in cardboard and plastic. This advice is limited to 2G Prius. I do not know whether the orientation changed for 3G.

The blade tension will be greater when the blade forms a "U", and then the blade is placed on the glass which reverses that to an upside-down "U". My guess is that the driver's side blade, being longer, needs that additional tension.

 

I recently replaced the inserts on all blades myself, thanks to the good ideas here. Were it not for this thread, I would never have known of the insert-only option.

The job did take far longer than I care to admit. My greatest difficulty was with the front driver side, getting the final clamp on blade to lock into the notches in rubber insert. In frustration, I asked a neighbor to try. Only through brute force did he get the two to come together. I struggled a bit with the passenger side as well but not nearly as long.

For future reference, I'd appreciate tips on what I may have done wrong. If it matters, my inserts came plainly packaged. There were no instructions, no pins, just pieces of rubber in clear plastic bags.

 

Repair Manual info, the really should be in the Owner's Manual:

 

Thank you, Mendel.
Agree, This really ought to be in the owner’s manual.