Farwell played at San Jose State in 2000 before transferring to San Diego State University. After sitting out the 2001 season due to NCAA transfer rules, Farwell debuted with the San Diego State Aztecs in 2002 as a sophomore. He was ranked 5th on the team with 59 tackles, and his three quarterback sacks were 4th in the Mountain West Conference among linebackers. During the season, he also recorded 10 tackles for loss, while having a season best eight tackles versus UCLA. His four forced fumbles were tops in Mountain West. The following year, he started six games at outside linebacker and finished the season with 52 tackles and 3.5 quarterback sacks. He also recovered two fumbles on the season versus Air Force and UCLA, and had a season high eight tackles versus Utah. As a senior, he started all 11 games for the Aztecs and was third on the team with 69 total tackles. He also added a team best seven sacks, two interceptions and forced four fumbles. Farwell finished his career with 180 tackles, 13.5 sacks and nine forced fumbles in three seasons at San Diego State.
