I accidently put windshield washing fluid in the radiator resovoir. It doesn't look like it has gone out of the resovoir though. It is ok if I just drain the resovoir and replace it with coolant?

You will be fine if no 'soap' water got in to radiator. Just drain overflow thoroughly. Then, especially if you never started the car, when cold, just add a little distilled water in to tank. If radiator is topped off, the tank should be no more than 1/4 full cold, so that little but won't throw off the mix enough to matter. Then, there is a difference of opinion about what coolant. http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1141798 ...but really should use Toyota coolant, does not mean you have to buy it at dealer, just read labels 'suitable for Toyota vehicles'