Richard Hirschfeld Williams (May 7, 1929 - July 7, 2011) was an American left fielder, third baseman, manager, coach and front office consultant in Major League Baseball. Known especially as a hard-driving, sharp-tongued manager from 1967 to 1969 and from 1971 to 1988, he led teams to three American League pennants, one National League pennant, and two World Series triumphs. He is one of seven managers to win pennants in both major leagues, and joined Bill McKechnie in becoming only the second manager to lead three franchises to the Series. He and Lou Piniella are the only managers in history to lead four teams to seasons of 90 or more wins.

In 1977, he returned to Montreal as manager of the Expos, who had just come off 107 losses and a last-place finish in the NL East. Team president John McHale and general manager Jim Fanning had been impressed with Williams' efforts in Boston and Oakland, and thought he was what the Expos needed to finally become a winner.  After cajoling the Expos into improved, but below .500, performances in his first two seasons, Williams turned the 1979-80 Expos into pennant contenders. The team won over 90 games both years--the first winning seasons in franchise history. The 1979 unit won 95 games, the most that the franchise would win in Montreal. However, they finished second each time to the eventual World Champion (the Pittsburgh Pirates in 1979 and the Philadelphia Phillies in 1980). Williams was never afraid to give young players a chance to play, and his Expos teams were flush with young talent, including All-Stars such as outfielder Andre Dawson and catcher Gary Carter. With a solid core of young players and a fruitful farm system, the Expos seemed a lock to contend for a long time to come.  But Williams' hard edge alienated his players--especially his pitchers--and ultimately wore out his welcome. He labeled pitcher Steve Rogers a fraud with "king of the mountain syndrome" - meaning that Rogers had been a good pitcher on a bad team for so long that he was unable to "step up" when the team became good. Williams also lost confidence in closer Jeff Reardon, whom the Montreal front office had acquired in a much publicized trade with the Mets. When the 1981 Expos performed below expectations, Williams was fired during the pennant drive on September 7. With the arrival of his easy-going successor Jim Fanning, who restored Reardon to the closer's role, the inspired Expos made the playoffs for the only time in their 36-year history in Montreal. However, they fell in heartbreaking fashion to Rick Monday and the eventual World Champion Los Angeles Dodgers in a five-game NLCS.

Using a quote from the above article, answer the following question: what did he do as manager of the expos?
Williams turned the 1979-80 Expos into pennant contenders.