The person performing wudu should cleanse their nose using their left hand. This is based on a narration from Sayyiduna Ali (may Allah be pleased with him), who is reported to have cleansed his nose with his left hand during wudu and said that this was the practice of the Messenger of Allah (peace and blessings be upon him).
[Musnad al-Imam Ahmad: 1/135, its chain is authentic]
[Musnad al-Imam Ahmad: 1/135, its chain is authentic]