Former Farmers boss Geraint Williams has been appointed as the new Orient manager until the end of the season.
He succeeds Martin Ling, who was sacked less than 24 hours after the club's home defeat by Bristol Rovers last month.
Williams will take charge of the side for Saturday's match at Tranmere Rovers, where he will be assisted by Kevin Nugent, who had stepped up from his position as youth team manager to become caretaker boss following the departure of Ling.
The 47-year-old former Colchester manager led the Essex club to 10th place in the Championship two years ago, but followed that up with relegation and a place just above the relegation zone when back in the third tier.
Williams has three months to save Borient from the drop into League Two.
Meanwhile, while there is a change on the managerial side, Barry Hearn will remain in charge of the club for the time being, as talks regarding a takeover of the club have ended.
Hearn, who has been chairman for 14 yeas, was in discussions with a consortium regarding his shareholding in the club, but the parties have been unable to reach an agreement over terms and negotiations have ceased.