The Messenger of Allah ﷺ, when he bathed after a state of major impurity, would begin by washing his hands. Then he would perform ablution as he did for prayer. Then he would dip his fingers into the water and run them through the roots of his hair. Then he would pour three handfuls of water over his head with his hands, and afterwards pour water over his entire body.
أن رسول الله ﷺ كان إذا اغتسل من الجنابة بدأ بغسل يديه، ثم توضأ كما يتوضأ للصلاة، ثم يدخل أصابعه في الماء، فيخلل بها أصول شعره، ثم يصب على رأسه ثلاث غرفات بيديه، ثم يفيض الماء على جلده كله.
Malik narrated it in "Purification" (67), from Hisham bin Urwa, from his father, from Ayesha, and through his route Bukhari narrated it in "Ghusl" (248), and in another version of his (272) through the route of Abdullah bin Mubarak, from Hisham bin Urwa with the same chain, she said, "Whenever the Messenger of Allah ﷺ performed ghusl from janaba, he would wash his hands, then perform ablution as he would for prayer, then he would wash himself, then run his fingers through his hair with his hand, until when he thought he had thoroughly wetted his skin, he would pour water over it three times, then he would wash the rest of his body."Muslim also narrated it in "Menstruation" (316) through several routes from Hisham, and in his version it reads, "Whenever the Messenger of Allah ﷺ performed ghusl from janaba, he would begin by washing his hands, then pour water with his right hand over his left and wash his private parts, then he would perform ablution as he would for prayer, then he would take water and work his fingers into the roots of his hair, until when he saw that he had thoroughly cleansed it, he would scoop water over his head with both hands three times, then pour water over the rest of his body, then wash his feet."In Bukhari's version it reads, "Until when he thought he had thoroughly wetted his skin, he would pour water over it three times, then wash the rest of his body."In another version of his, also from Ayesha (321), "Whenever the Messenger of Allah ﷺ performed ghusl, he would begin with his right hand, pouring water over it and washing it, then he would pour water on the impurity that was on his right hand and wash it off with his left hand, and when he had finished with that he would pour water over his head." And she said, "I used to perform ghusl together with the Messenger of Allah ﷺ from a single vessel, while we were both in a state of janaba."In another version, she said that she and the Prophet ﷺ used to perform ghusl from a single vessel that held three mudds, or close to that.In Sunan Abu Dawud (242), "If any water remained, he would pour it over his head."As for her statement, "then he would pour water on the impurity," she may have meant by this the private parts.