I would partly privatise it immediately, incentivise the public to take out insurance, cut out a lot of the NHS services, cut waste, allow a better referrals process that doesn’t involve GP gatekeepers, expand GP hours but pay them more to incentivise them and require all GPs to modernise with streamlined technology.
Then I would focus on public services to improve health and disincentivise unhealthy habits. Invest in development which is designed around walking and cycling, improve walking routes, widen pavements, improve cycling routes, set up bike buses and walking buses for schools, expand public fitness centres and pools. Invest in really healthy school and college meals and teach children about healthy eating by offering them delicious healthy food. Then tax sugar, tax ready meals, tax fast food, block fast food near schools and colleges, tax alcohol, ban cigarettes and ban vapes.
The public would hate me but I am not messing about!