I recycled a 2011 27" iMac with two drives, one SSD and one rotational but not a Fusion drive. The rotational drive was easily found and removed. However, the SSD was under the motherboard which was difficult to remove. Since I was only recycling the unit I didn't have to worry about putting it back together correctly so just sort of "ripped" it out.
So look under the motherboard for the SSD. If you're just recycling it and don't have to have it in working order don't worry about ending up with extra screws, etc. Just put it together with masking tape and recycle. rkaufmann87's suggestion of having Apple send you a shipping container might be what you want. Since the Apple Store was very close to our home I just drove up, double parked and they came out and took it in.
Good luck.
