How do i convert a skin for 1.8

HOW DO I COMVERTER A SKIN FOR 1.8 no longer appears the option to convert to 1.8

covert a pre 1.8 skin to 1.8?

drag skin to editor and save?

I think you mean the opposite, convert to pre 1.8 skins.
Use the old editor if you need 1.6 compatibility.

This, is gone.