The former Albion caretaker boss is set to be appointed boss of Solihull Moors, who play one division above Harriers in the National League Premier.
Russ Penn has now been appointed manager at Aggborough until the rest of the season, becoming the club’s fifth permanent boss in little more than a year.
Harriers interim CEO Neil Male said: “Jimmy has moved onto pursue a football career opportunity at a higher level.
“I would like to personally thank him on behalf of the club for his time with his input and assistance over the last three months.”
Shan added: “I want to make a special reference thanking the fans, players and staff during my time at the club.
“I am convinced, under the new ownership and direction, the club is heading in a positive and progressive manner to bring back the success the fans deserve.”
Penn was previously made caretaker boss following John Pemberton’s departure in November, after just six months in charge.
He then became Shan’s assistant when the latter joined the club in early December.
The job at Aggborough marked a return to football for Shan after leaving Albion last summer.
A long-time member of the club’s academy staff, he took over as caretaker boss at The Hawthorns following Darren Moore’s sacking last March, guiding the Baggies to a narrow play-off semi-final loss to Villa.