HOUSTON --Mario Williams peppered Houston Texans linebackers coach Reggie Herring with questions about his pass-rushing technique after the team's first practice. The 6-foot-6 Williams, a defensive end and the Texans' sacks leader in each of his five seasons, is moving to outside linebacker in new defensive coordinator Wade Phillips' 3-4 scheme. His transition is a key to the improvement of a defense that ranked at or near the bottom in most categories in 2010. Williams, the top overall pick in the 2006 draft, said Monday that "little things seem kind of difficult," but the position change won't be a major adjustment. Williams says the biggest difference is standing up instead of starting from a 3-point stance.