They have been without a full-time boss since parting with Harry Wheeler in December.
The Stones are in the National League relegation-zone and on Saturday went down 3-0 at home to Dagenham.
Stand-in Simon Walton will have a player-coach role within the new set-up but there will be a new manager arriving tomorrow.
Chief executive Bill Williams said: “We expect to announce the appointment of an experienced new Head of Football tomorrow, who will be responsible for the team selection and recruitment of all professional players at the club.
“The club expect also to be able to announce the full management team, which will include Simon Walton as a player-coach.
“The new Head of Football intends to appoint a Head Coach and a scouting organisation as part of his team.
“Meanwhile, Tristan Lewis has left the club. We thank him sincerely for his enthusiasm, commitment and positive attitude and wish him well in the future. All agreements are in place, subject to contract.”