If your symptoms (chest discomfort) are relieved with medication, that would be an option. If not, I think a stent should be considered if possible.
Lifestyle changes can be beneficial and will help to avoid worsening of the situation. It will not cure the already present blockages.
My cordiologist advise:
Medical management and life style modification advised. No need for any intervention at the movement
The angiography report does not describe very severe blockages, but as you mention symptoms of chest pain, the blockage in the first diagonal of the LAD (D1) must be the main cause of it.
The LAD supplies the anterior wall, so the hypokinesia of that part of the heart and the lowered EF (normal range 55-70%) could be explained by the stenosis.
I guess the quickest and most obvious solution would be to place a stent in the stenosed area. What did your cardiologist advice?