what do you mean?
Just take the map folder and put it in the "C:\Users\YOUR_USERNAME\AppData\Roaming\.minecraft \saves" directory.
Type it in the url bar of explorer cause the AppData folder is hidden. I'm too lazy to explain how to show it.
Is it a World Save? If so Do what was said above ^
If it is a Schematic then you have to use MCedit and use the schematic place it and then go back into minecraft...