Short answers, pulled from the story.
Mikhail Gorbachev announced the end of the Soviet Union in December 1991. This decision followed a meeting in Alma-Ata where leaders from Ukraine and Belarus declared the 1922 treaty of union annulled.
On the 3rd of October 1993, tanks fired on the White House under the direction of Minister of Defense Pavel Grachev to dissolve parliament. Military forces occupied the building and the rest of Moscow after firefights resulted at several locations.
Vladimir Putin won the first presidential election held on the 26th of March 2000 with 53 percent of the vote. He had previously been made Prime Minister of Russia before acting president following Yeltsin's resignation.
Ruslan Khasbulatov served as Chair of the Supreme Soviet and became Yeltsin's most vocal opponent during the September and October 1993 events. Under the 1978 constitution, the parliament was the supreme organ of power.
The Law on Presidential Elections was ratified in May 1995 and established the legal basis for elections. Alterations included reduction in signatures required to register a candidate from 2 million to 1 million.