Exchange the engine in a vehicle for another by completely disconnecting all of the original engine's connections and unbolting the engine from the frame of the vehicle. Use an engine lift to safely remove the old engine from the vehicle. Again using an engine lift, install the replacement engine, and attach all necessary components including electrical wiring, air and fuel hosing and drive train. Ensure the engine is bolted to the frame securely before starting or driving.
Before doing any work on the engine swap, measure the original engine, the space under your hood where the new engine will be mounted, and the new engine to make sure that it will fit properly. Make note of any discrepancies between the original engine's mounting positions and the new one's. In the event that the engine being swapped in is a larger and heavier engine than the original, it is necessary to use aftermarket engine mounts to ensure the proper strength and rigidity to hold the new engine.
The transmission may need to be altered or swapped to make the most of the newly installed engine to account for increases in torque and power. Swapping the vehicle's gearing causes the engine to shift at different intervals and distribute the engine power amongst each of the gears in a customized fashion. This is an especially useful and common practice when building drag or race cars.