How to cure intermittent claudication and get active again?

Depends.... There are basically 2 types of claudication: one from compression of your spinal cord and the other from lack of blood flow. The former generally causes pain in the legs when standing and doesn't go away with rest. It requires a physician evaluation. The latter is best treated with exercise. Of concern is the existence of heart disease and risk of stroke in this case - see your doctor!
Depends. It depends on where the blockages are and how severe. Sometimes medical therapy and a walking program are effective. Smoking cessation is an absolute requirement. Angioplasty/stenting may be indicated and even surgery. See your doctor asap. Claudication is often a marker of coronary artery disease as well.