Pelaez and Yon de Luisa, named operations president, will work together under a council of directors headed by Emilio Azcarraga, the Azteca based club's owner and president of the powerful media organisation Televisa.
"I have brought a magic wand to resolve the situation, I want to build a competitive working group. Work and humility are the words that will set our path," the 48-year-old told reporters after his presentation.
America, one of Mexico's two biggest and most successful clubs with arch-rivals Guadalajara, are at one of their lowest ebbs after finishing one from bottom of the league standings and failing to reach the Apertura championship quarter-finals.
De Luisa announced the dismissal of Tena and Pelaez's initial tasks will be to find a new coach, give the squad a solid Mexican base plus a few foreign signings and win as many titles as possible in the run-in to America's centenary in 2016.
"Things couldn't be worse, there is great concern over the spiritual aspect [of the team]. We'll try to build a good team in quality and quantity," said Pelaez, who played for America, Necaxa, Guadalajara and Mexico at the 1998 World Cup in France.
"To be at America is a privilege, some will go others will come in. I think there's a very good squad, we have good players [but] I also think that in some areas of the pitch we lack a player who can tip the balance [favourably]," he said.
