I haven't gotten my 4.3 update yet I am using the Sprint Galaxy S4 I tried Update Samsung Software and Update Firmware no updates and my phone is still 4.2.2
Go to xda developers...download ota...move to SD card, boot into download mode and "update from zip" no fuss no muss. If you don't want to do that...see if your local best buy has a Samsung experience store...take it there any they can flash it for you
Another way is to continually clear cache and data out of Google services framework over and over, each time searching for update after clearing. It took me three times and then it showed up
Ok fellas all these links were posted on the front page the day the announcement came out that Sprint was getting the update. Like ya'll I waited all weekend and then decided to watch the Youtube video which explains how to manually do the update. If you know how to do it then you just download the 4.3 file from here which is from XDA and install it onto your sim card.
Another way is to continually clear cache and data out of Google services framework over and over, each time searching for update after clearing. It took me three times and then it showed up