Williams, who was the team's offensive co-captain, was suspended for the final four games last season after repeated failed drug tests and is enrolled in the league's substance abuse program.
Williams is now charged with protecting the blindside of second-overall pick Robert Griffin III.
"It is what it is," said Williams, the first time lineman had spoken with the media since his suspension. "I made a mistake. I've just got to deal with it."
Williams, who was playing in teammate Brian Orakpo's Leukemia Golf Classic when he spoke with reporters, said it was time for him to take on more responsibility.
"Be more of a leader," Williams said. "Obviously not make the mistakes I made in the past. Just be a better player and lead by example."
Williams, who was the fourth-overall pick in the 2010 draft, said he was excited to get back to work after watching form his couch during his suspension.
"I can't wait," Williams said. "We've got a new quarterback, a whole new team. It's going to be fun."