How do doctors put pacemakers in?

Carefully! Most commonly one, two, or three insulated wires are placed through the left or right subclavian vein (runs under the clavicle) using a large bore needle and plastic tubes (sheaths), and then a pocket is created in the area about a half inch below the clavicle where the wires will be connected to the generator and the generator is placed in the pocket and closed.
Pacemakers. A small pocket is created under the skin in the pectoral area and a wire is snaked through ond of the large veins in the chest and lodged in gone spec of the right ventricle and the other end is attached to a generator and buried in the pocket.
Usually minor. Pacemakers consist of a generator and leads. The leads go in to the right side of the heart from the subclavian vein and the generator goes under the skin under the collar bone. Once the leads are healed and fibrosed only the generator will need to be replaced when the battery runs low.