First of all there will be no sannyasi anymore
In the varṇāśrama institution the sannyāsī, or the person in the renounced order of life, is considered to be the head or the spiritual master of all the social statuses and orders. A brāhmaṇa is considered to be the spiritual master of the three other sections of a society, namely, the kṣatriyas, the vaiśyas and the śūdras, but a sannyāsī, who is on the top of the institution, is considered to be the spiritual master of the brāhmaṇas also. For a sannyāsī, the first qualification should be fearlessness.
Because a sannyāsī has to be alone without any support or guarantee of support, he has simply to depend on the mercy of the Supreme Personality of Godhead.
If he thinks, "After leaving my connections, who will protect me?" he should not accept the renounced order of life.
One must be fully convinced that Kṛṣṇa or the Supreme Personality of Godhead in His localized aspect as Paramātmā is always within, that He is seeing everything and He always knows what one intends to do. One must thus have firm conviction that Kṛṣṇa as Paramātmā will take care of a soul surrendered to Him.
"I shall never be alone," one should think. "Even if I live in the darkest regions of a forest I shall be accompanied by Kṛṣṇa, and He will give me all protection." That conviction is called abhayam, without fear. This state of mind is necessary for a person in the renounced order of life.
Then he has to purify his existence. There are so many rules and regulations to be followed in the renounced order of life.
Most important of all, a sannyāsī is strictly forbidden to have any intimate relationship with a woman. He is even forbidden to talk with a woman in a secluded place. Lord Caitanya was an ideal sannyāsī, and when He was at Purī His feminine devotees could not even come near to offer their respects. They were advised to bow down from a distant place. This is not a sign of hatred for women as a class, but it is a stricture imposed on the sannyāsī not to have close connections with women. One has to follow the rules and regulations of a particular status of life in order to purify his existence.
For a sannyāsī, intimate relations with women and possessions of wealth for sense gratification are strictly forbidden.
The ideal sannyāsī was Lord Caitanya Himself, and we can learn from His life that He was very strict in regards to women. Although He is considered to be the most liberal incarnation of Godhead, accepting the most fallen conditioned souls, He strictly followed the rules and regulations of the sannyāsa order of the life in connection with association with woman. One of His personal associates, namely Choṭa Haridāsa, was personally associated with Lord Caitanya, along with His other confidential personal associates, but somehow or other this Choṭa Haridāsa looked lustily on a young woman, and Lord Caitanya was so strict that He at once rejected him from the society of His personal associates.
Lord Caitanya said, "For a sannyāsī or anyone who is aspiring to get out of the clutches of material nature and trying to elevate himself to the spiritual nature and go back to home, back to Godhead, for him, looking toward material possessions and women for sense gratification-not even enjoying them, but just looking toward them with such a propensity-is so condemned that he had better commit suicide before experiencing such illicit desires."
So these are the processes for purification.
(Srila Prabhupada: Bhagavad-gita As It Is 16.1-3, original edition Macmillan 1972)
However, Srila Prabhupada saw that actually no one was qualified to take sannyasa, and therefore he actually stopped it altogether in ISKCON after 1977, and so it should not be occurring now:
From this we can understand that in this age the sannyäsa-äçrama is forbidden because people are not strong. Çré Caitanya Mahäprabhu showed us an example in taking sannyäsa at the age of twenty-four years, but even Särvabhauma Bhaööäcärya advised Çré Caitanya Mahäprabhu to be extremely careful because He had taken sannyäsa at an early age. For preaching we give young boys sannyäsa, but actually it is being experienced that they are not fit for sannyäsa.
“If you talk in the modern society they will laugh: “What nonsense this man is... ‘By sex life one becomes conditioned.’ “ They cannot understand. Hare Krsna...This should be strictly outlawed, no more sannyasis. And those sannyasis who have fallen, you get them married, live like a... No more this showbottle, cheating. It is very ludicrous. Even there is a promise that “We shall not fall down again,” that is also not believable. What is the use?”
(Srila Prabhupada Conversation, 7/1/77)
“And this kind of hypocrisy--they have taken sannyasa and mixing with woman. This is not to be allowed. If you want woman you get yourself married, live respectfully. We have no objection. But this hypocrisy should be stopped. There have been so many fallen down. First of all there will be no sannyasi anymore. I have got very bad experience. And at least, we are not going to create new sannyasis. And those who have fallen down, let them marry, live like respectable gentlemen. I have no objection. [...] Get one wife and live like a gentleman. Similarly woman. Live with one husband fastidiously, with children. What is the wrong there? We have so many grhastha devotees. [...] But what is this nonsense that you take sannyasa and make relation with...? This should be completely stopped.”
(Srila Prabhupada Conversation, 7/1/77)
Mahesh Raja P.: Sannyasa Asrama 5 parts:http://www.prabhupadanugas.eu/news/?p=42332