How to add a rig to a complex character?

I'm trying to add a rig to a fairly complicated human character, and I've simplified it as much as i possibly can, but I still cant apply the rig. It's a human character wearing a shirt and tie, with suspenders. His sleeves are rolled, and theres pinstripes on his pants. Thats the extent to which it's "complicated." It says the shapes are still too complex. Help?