/cgl/ - Cosplay & EGL

I found a perfect jacket for picrel, the only catch being that it is pretty large on me. I'm not the greatest at sewing, and I've only worked on small additions and repairs, but if possible, I would really like to resize my jacket to be at least somewhat form-fitting, and possibly replicate the bell-shaped sleeves as seen in the pic.

Does anyone know of some good tutorials/resources that might help me do a decent job of resizing this coat?