So clockwise
1. Hound's Head
2. Nemesis Breaker's hands/claws
3. ? - Unknown Leg
4. RiD Prowl's left forearm/hand
5. RotF (Cannon?) Bumblebee's right leg
6. ? - Looks like a missile launcher
7. Energon Hot Shot's right arm (Isn't that the one Megatron removed?)
8. BW Blackarachnia's right leg


And just to note, I think this one is about right in the difficulty level - not too easy, but easy enough to recognise the pieces.