Quote from Minecrafter1912
You just have to drag-drop the file into your mods folder. But make sure that you are using Forge #897+
Similarly to the other person and what you said, I've tried both. Gonna attempt it a few more times, but Forge seems to not be picking up Optifine in any way or form at all.
I'm also going to try it the old, manual way if that doesn't work either...