From where to download xcode 5?
Xcode 5 can be downloaded only from the Mac App Store or from the Apple Developer site. 

You could create an Apple ID and use the Mac App Store to download it.  

OR  


You could create a free developer account at the Apple Developer portal
go to the downloads section
check only Developer Tools under Categories on the left (uncheck others, to make it simpler to find)
then download the Xcode 5 DMG file.