The sentencing of co-accused Junior Bradshaw, 32, was adjourned.
The pair, of St Stephen's Close, Longsight, in Manchester, harboured a deep hatred for the soul artist, the three-week trial at Exeter Crown Court heard.
They were convicted of conspiring to rob and kill the star last summer, they were then planning to dump her body in a river.
The pair set off from their home in Manchester with a samurai sword, knives, bags and gloves crammed in their Fiat Punto, bound for Miss Stone's address in mid-Devon.
However, their plan to rob and kill Miss Stone - whose birth name is Jocelyn Stoker - was fraught with problems.
They became lost around seven miles from Miss Stone's home and stopped to ask postman Alex Greening for directions to the property in Ashill, showing him a map with handwritten notes on it, as well as a picture of the 25-year-old celebrity.
The pair had earlier been stopped by police at the M5 Michaelwood services in Gloucestershire at 5am after their Punto crashed into metal railings and a digger.
Officers thought the car was too badly damaged to be driven and left - but the pair continued their journey south.
They were arrested on June 13, 2011, a few miles from Miss Stone's home when concerned local residents - spotting their crash-damaged car - called police.
The suspicious uniformed PCs discovered Bradshaw did not have a driving licence and arrested him.
They searched the Punto and found a stash of weapons, including a black-handled samurai sword, three knives, a section of garden hosepipe, two hammers, black gloves and balaclavas.
A further holdall contained a metal spike, black bags and black tape. There were also printouts of AA routefinder maps from Manchester to Devon.
Notes made by Liverpool - who was branded a fantasist by his own lawyer - found in the car and his flat in Manchester included references to robbing, killing and beheading the singer.
Rambling handwritten diaries were also discovered, in which he highlighted the need to buy a semi-automatic gun, a silencer, infra-red sights and a "ninja" sword.
He called Miss Stone "princess" and other entries referred to "Jocelyn RIP - try to get info. Rob and kill". They also referred to her as a "She devil in flesh".
Giving evidence to the court, Miss Stone admitted there was lax security at her home, but said she only learned of the plot against her from police.
"I had an alarm but I did not really turn it on very much. I didn't really have a lock on my door ... But I do now."
Bradshaw and Liverpool denied charges of conspiracy to murder, the alternative charges of conspiracy to cause grievous bodily harm and conspiracy to rob.
Defending Liverpool, Philip King QC, said the plot to kill Miss Stone was nothing more than a bungled "fantasy" that was never going to be carried out.
Bradshaw, who has spent time detained under the Mental Health Act in psychiatric units, said he had never heard of the singer until his arrest and that he believed he was on a day out with his friend.
In a statement after the verdicts, Miss Stone said: "I am relieved the trial is now over and that these men are no longer in a position to cause harm to anyone."
