2009 Prius - Key Fob Problems

I bought a new 2009 Prius in December 2008. The key fobs have started giving me trouble, sometimes the doors won't open when I try (keyless entry), sometimes the car won't start unless I insert the fob in the slot, sometimes the push button locking of the doors, after I get out of the car does not work. It's very random, but now, more often these things will not work, the times they do are the exceptions. Also, sometimes locking or unlock the car, pushing the buttons on the fob, does nothing.

What is the most likely problem and what are my options for resolving this? Would this be covered under the regular warranty or the Toyota Extended Warranty I got from Troy Dietrich, through this website?

 

The other fob acted up first, then I switched and now this one is acting up. All this over months or even the last year or two. No, I have not changed the battery. How can I do that? Are there instructions on this site somewhere?
Thanks!

 

nh70, thanks I found a how to video on You Tube. I could not find instructions here. One reason I hadn't thought of the battery in the fob was that I was worried it was an item that had to be done by the dealer. I see from reading some comments at the You Tube video this is not the case. Although a few, less-than-honest dealers have tried to convince people they had to have it done at the dealership. Also, since there is a metal contact when you put the fob in the slot, I thought that perhaps, just maybe, that might serve to recharge the battery, in some fashion.

 

Thanks. Of course, the video is really helpful, as well.

 

Thanks to all who contributed. I changed the battery in both key fobs and it is working much better.

dorunron - I had the 12v aux battery changed last year. It died while I was driving, towed to Toyota and that was the reason, so I had them change it.