I would...
1. Prime the whole piece black
2. Silver or grey coat on all major armor pieces+some smaller areas.
3. black wash
4. Go over only the major amor pieces that would get light with another layer of silver or grey.
5. Highlight white mixed with silver or grey
6. Paint any of the finer details such as scrolls, eyes, weapons, ect.
7. Paint/finish the base.
Hope this helps.