Challenging question
A comprehensive answer would be quite lengthy and a lot of work, assuming I had the wherewithal to do it competently. I do have some ideas to offer though. Basically it’s a culture shift, accepting guns as necessary rather than believed to be inherently bad. Armed police are not the only good guys.
1. Prevent insurance companies from ultimately controlling the outcome. That is pro-crime. No clauses or riders excluding deadly force for self defense. No declaration of fireams required. No civil suit liabilities. No bogus cancellations after the fact.
2. Sponsor gun ownership locally through the police department, offering safety training, gun orientation, and self defense classes. Each locality should have one or more publicly supported shooting ranges as a standard community service.
3. Reduce addicted desperation. Offer rewards for tips leading to drug dealer convictions, including witness protection programs. Also include incentives for identifying users of particularly addictive and expensive drugs, who would be subject to mandatory intervention programs, publicly funded. After one session AND being of legal age, they're on their own (community parenting).
4. Give disadvantaged cultures something better to which they can aspire than working the system or being a criminal.
5. Invest in law and order. That might include conceding that more citizens should carry guns.
6. Carefully define the principle of a righteous shoot, being careful not to demonize the act of shooting someone, acknowledging that it is sometimes necessary. Protect the innocent, not the guilty. The justification for shooting someone should be straightforward. The shooter should not automatically be in legal trouble at great personal expense. A sympathetic or at least objective jury should not be hard to find, if it goes to court. Minimize civil liability.
7. Someone in the act of committing a felony in a person's home should have no rights if proven guilty. His family should have no recourse either. Homeowner liability and subsequent lawsuits are a travesty. The guy breaking his leg coming through your window is SOL.
8. End the "only shoot to stop" argument. That principle over used is hostile to gun owners in a very high stress situation. Bang, you're dead. No surprise. No tears. No enjoyment either.