First, the shop/installer that's doing the wrap washes the vehicle and details it with a clay bar to remove any contaminants from the surface of the paint. Some installers use a solution of isopropyl alcohol to clean the paint then blow off any remaining dirt particles with compressed air.
The shop/installer then removes the bumpers, headlights and taillights so that the installer can apply the wrap as close to the edges of the body panels as possible. If a customer doesn't feel comfortable with the shop taking the car apart, the installer will bypass this step and instead use a scalpel-like tool to cut the vinyl around the lights and grill.
The installers then apply the vinyl wrap to the body of the vehicle. They use a heat gun to make the material more pliable, so it can properly hug the contours of the vehicle. Some of the more advanced wrap designs, such as those using graphics or custom colors, will require additional vinyl layers. Finally, the installers use a soft felt squeegee to remove any air pockets.
The whole process can take a few days to complete. It's longer if you want the doorjambs (the inner body-colored part of your doors) to match. The doorjambs alone will take an extra day and a half depending on the installer. The doors need to be taken apart before being wrapped, which adds more labor and cost to the installation. Black cars make the ideal candidates for wrapping: The doorjambs are less noticeable and you don't have to spend any extra chee$e for them to be wrapped.