I as King would:

1.Call up for national service avery one who knows how to use a longbow, a billhook, a sword or ride a horse.
2. Assert my claim on France.
3. Invade France.

Do not tell me that I hate France, because I love it. I love it so much I want to have every village in it.........

On a more serious note:
1. Make myself the supreme ruler.
2. Organise a new economic plan. This includes of raising millions of punds in bonds as capital. Then this money would be invested in various sectors of the market. The people with the bonds would be given interest on the money lent and any money made would serve to nationalise things such as the railways. These would be run by a Swiss. The money would also be used to improve health care, education, police force, armed forces and so on. The rest would be used to buy more shares/companies. Since the money is invested in various sectors, the likelyhood of a loss is reduced.
3. Return to the grammar school/secondary modern system, where the secondary moderns focus on manual skills such as carpentry.

Of course, there's much more to do such as reinstating the death penalty for murderers, serial killers,traitors to the state and people who like Fiat cars. Corporal punishment should also come into force for yobbism and so on. Rapists and paedophiles should be castrated.