I just found this on Civfantics .com about modding for Civ 5 using Modbuddy = Civ 5 SDK.
NOTE: Sometime prior to September 2013, Microsoft removed
the main page for their Visual Studio 2010 Isolated Shell
Redistributable. This must be installed for ModBuddy to work. For the time being, the English version is still available from Microsoft. You can also get it from Hulfgar here or from me here. If you are looking for a non-English version, I am sorry to say, good luck with your search.