How would I advise the Roman Catholic Church?
First, end the schism. Admit protestants to full communion, and do so in the following way. Give discretion to local bishops to set their own guidance on who can receive the Eucharist. Many of the bishops already exercise this discretion; they’re just called Methodists or Baptists, etc. Issue guidance from Rome for those bishops who choose to follow it, and that guidance is to administer the Eucharist to all those who accept Jesus Christ as their Lord and Savior. Don’t excommunicate anybody if they won’t do this.
Next, open the religious communities to couples and families. Presumably they were already opened to protestants in the first step. Recognize that the “widows” spoken of in Acts 6:1 were probably admitted to the church in that state – it wasn’t old enough for them to have joined as young women. End the caste division in the church where we have religiosos and laity. Religious community, in some form or another, is the preferred organizational style for the saints.
Communities will probably attract a crowd of homeless followers. They should be accommodated to the greatest extent possible. Provide space for tent cities, and don’t neglect the need for basic hygiene such as toilets and showers. Organize food banks and community feedings.
Preach the authentic Christian gospel. Quit focusing so much on sexuality and teach against the economic immorality of the majority. Our default answer to most requests should be “yes, of course” instead of “here’s how much it will cost”. It’s so hard to believe that God will give us the greatest gift of eternal life for free, when we won’t let people fly on an airplane for free.