Lots of reading through the material and practicing questions. In honesty, the initial orgo class was somewhat difficult, but after I understood the concepts it was easy. But now my focus for my chemistry major is organic chemistry, so I might be a little bias.
If you struggle initially, you might expect to spend at least 5-6 hours or maybe 10 per week (but that might be a guess on the high end).
Stay on top of the material, ask question if you don't understand, and practice exercise questions in the back of each chapter.
What is your major?