I, and my peers, experienced bullying by my boss. But I managed to control him and stop his actions. It's one of the hardest situations I faced. Do not let be bullied into silence.
Believe it or not, I successfully used Aikido principles. It's then that I realized the essence of aikido's philosophy even in a non-physical confrontational setting.
Stance. When facing him use an assertive, not aggressive, stance similar to kamae, but only in the mind. Standing, sitting in presence of or walking towards the bully, it's important to assume a straight assertive posture always keeping kamae in mind.
Being Nage. Keep eye contact, track him and do not look away when interacting with the bully...similar to facing uke always anywhere when performing a technique.
Turn him into your uke. Challenge/defeat him (throw him) but do not let him lose face (still protect). I think I did it by being frank about the situation but still being professional.
Attack his blind side. Give him just a hint of what you might do and what you are capable of. Make him be the one uncomfortable when he's dealing with you (similar to uke being in a disadvantaged position during a technique).
Strong Intent. Have strong intent that if he wants to wrong you/start his bullying that you will fight back and he most likely will lose or meet his match, but only through intent and body language. The fight is won before it's even begun. Be strong inside and do not show weakness. Stay centered and relaxed. The bully can actually sense tension and can take advantage of this to start his bullying.
Defense. Do not use confrontational language but be very assertive. Perform verbal kaeshiwaza.
Atemi/preemptive strike. Find his openings/weaknesses and report his actions to HR.