Wing Fu Cheung, also known as Nelson Cheung, was stabbed to death after his car was forced off the road outside Randalstown in January 2015.
The 65-year-old Ballymena man ran the Double Value Chinese takeaway restaurant in Randalstown.
Gary Thompson, 34, pleaded guilty to three charges lat Belfast Crown Court.
He was previously accused of Mr Cheung's murder, but that charge was left on the books.
Gary and Lisa Thompson had been due to stand trial and a jury was sworn in yesterday, but they were re-arraigned today.
Both were released on continuing bail, to be sentenced at a later date.
Gary Thompson, formerly of Cunningham Way in Antrim, admitted robbing Mr Cheung's wife, Kam-Fung Cheung, also known as Winnie.
He also pleaded guilty to assisting offenders by allowing two men who have admitted the murder - Virgilio Augusto Fernando Correia and Christopher David Menaul - to take refuge in his home, as well as letting them remove clothing and clean themselves after the killing.
Thompson also admitted perverting the course of justice by threatening Correia in an attempt to stop him talking to the police.
Lisa Thompson, 34, from Erskine Park in Ballyclare, admitted assisting offenders, handling stolen goods and perverting the course of justice.
The offences happened between 6 and 9 January 2015.
Last month, 35-year-old Correia admitted killing Mr Cheung, wounding his wife with intent to do her grievous bodily harm, and robbing her.
In November, 25-year-old Menaul pleaded guilty to the same three charges.
Both men are in custody, on remand, awaiting sentence.
A county Antrim husband and wife have admitted helping the murderers of a Chinese restaurant owner try to cover up their crime.