As for modernizing the British army, it is simple ... abolish it. The British army exists as a modern regiment of Hessians to supplement US requirements. (The same may be said of the Bundeswehr, unfortunately.) Otherwise the UK army has been worthless since the end of the First World War, when it was effectively finished, and survived only in later years because Hitler's absurd 'Aryan' sentimentalism enabled an evacuation from Dunkirk. Killing Irish civilians and people in Malaya and Kenya, but getting booted out of places where there might be serious consequences (e.g. Hong Kong) is not something of which to be proud.
The UK army is a hangover from days gone by, from the days of Wellington. But those days are no more. It is not needed any longer.
Soldier, can't lie to you -- most idiotic plan, hence disapproved!