"It's a hard situation, I have failed to find a stable job here, and I depend mostly on my relatives and friends to survive," Ndikumana, 24, told IRIN in Kigali.
He was just 14 when his uncle recruited him into the Forces Démocratique pour la Libération du Rwanda (FDLR), founded by Hutus who fled Rwanda in 1994 after taking part in the genocide. The movement remains a primary source of insecurity and human rights abuses in eastern DRC.
Ndikumana says his uncle convinced him of the need to topple the Tutsi-led regime that took power in Kigali in July 2004 so that all Hutu refugees in DRC could return home.
"My uncle convinced me our land had been taken over by the Tutsis. At that time, I saw it necessary to join the struggle," he said.
During his first months with the FDLR, he was not engaged in active combat operations because of his age, but he was given a rifle the following year.
In recent years a steady flow of FDLR members has taken part in demobilisation and return programmes, even if the group still has about 6,000 armed fighters in eastern DRC.
In February 2008, Ndikumana was among 500 FDLR members handed over by MONUC, the UN Mission in DRC, to Rwanda's Demobilisation and Reintegration Commission.
Their first stop was to Rwanda's Northern province, where they underwent a three-month rehabilitation, including counselling sessions, and training in literacy as well as other basic skills.
According to Jean Sayinzoga, chairman of the commission, the training offers the demobilised combats skills to cope with civilian life after spending years in the bush.
"You cannot just throw an ex-combatant into civilian life; we try to make them ready for the new life psychologically and socially," he told IRIN.
However, because most combatants have been in the bush with no access to education, it is hard for them to find meaningful jobs after demobilisation.
According to Sayinzoga, many of the ex-child militias have been sent to school and most have graduated in various fields; however, the situation is bleak for the older ex-fighters who lack qualifications and are unable to go to school.
Nevertheless, Sayinzoga said the government had helped most to acquire land to farm.
After the three months' rehabilitation, the combatants are given an initial package of 100,000 Rwanda Francs (US$180) followed by Fr150,000 ($270) for six months.
However, most combatants have failed to settle down due mainly to a lack of jobs and large numbers have moved to the capital in search of piece-work.
Pontien Kanyankole, another ex-combatant, said after failing to find a permanent job since June he had decided to settle for casual jobs in Kigali to survive.
"Every morning, I go around looking for something. On a good day, I can earn around Fr1,000 [$1,80]," he said, adding that he was still waiting for his final resettlement package to work out his next move.
The DRC government has repeatedly pledged to forcibly disarm the FDLR - to which it was allied during the 1998-2003 civil war - if its members failed to demobilise voluntarily.