Dennis Grenne has left the manager's post at Hemel Town with ex-Barnet goalkeeper Gary Phillips coming in to take his place.
Chairman Dave Boggins cited a clash of personalities for Greene's departure from Vauxhall Road on Thursday afternoon.
"Dennis and myself parted company due to an inability to get along with each other," said Boggins on Friday morning.
"We kept having a clash of personalities."
Greene joined the club towards the end of May after the departure of previous boss Paul Byrne.
Phillips, who managed the Tudors for a short spell in 2001, was a free agent when Boggins made his approach on Thursday afternoon.
He took his first training session with the players that evening.
He has become the fourth manager in just over seven months at Vauxhall Road.
Phillips was until recently manager at Grays Athletic, but parted company with the Conference club after new owners took over.
He will be working with a squad almost unrecognisable from that of last season with the departure of all but a handful of the squad built by Steve Bateman, who left the club in February.
Hemel Town are currently 14th in the Zamaretto Southern Premier League.
The new man's first game in charge will be at home to Hednesford Town on Saturday.
For more reaction and the first, exclusive interview with the new coach, see The Gazette.