How did Russia move from a czarist regime to a Communist regime?

The Bolsheviks seized power on 7 November 1917. The Congress of the Soviets declared itself to be the repository of all power and established a government called Council of People’s Commissars, composed solely of Bolsheviks, headed by Lenin.

It’s most important members were Rykov, Trotsky, Stalin and Lunacharsky. Immediately on coming to power, they renamed themselves Communists. They also shifted the seat of Government from Petrograd to Moscow.