Short answers, pulled from the story.
Mikhail Gorbachev announced the word demokratizatsiya in January 1987. This announcement marked a new direction for his country and introduced democratic elements into the single-party system.
The 19th Party Conference met in June 1988 as the first major gathering since 1941. Delegates discussed sweeping structural changes including multicandidate elections and separating government apparatus from party bodies at the regional level.
The Central Committee plenum approved the repeal of Article 6 of the constitution in February 1990. This action removed constitutional guarantees that had kept the party supreme since 1936 and legally dismantled its monopoly on power across the Soviet Union.
Boris Yeltsin led the Inter-Regional Group which was formed in summer 1989. The group included almost all liberal and Russian nationalist members of the opposition who sought to repeal Article 6 of the constitution.
Genuine reformists won only around 300 seats out of thousands available in the March 1989 election. Despite these actions, the resulting Congress still contained 87 percent Communist Party members.