what you do is this:
1. open appdata
2. go to roaming, .minecraft
3. click on versions then copy the files in 1.6.2
4.rename the .json and the .jar modded 1.6.2
5. open the .json file with notepad++ link here:
http://notepad-plus-plus.org/download/v6.4.2.html6. go to id and type in the quotation marks modded 1.6.2
(it is case sensitive)
7. save the file then close it and open the launcher
8. click on new profile and find new version
9. click modded 1.6.2
10. the modded 1.6.2 file in versions on .minecraft will be the .jar you put the mods in
that is all you are done!