The tail light part alone costs around $15 to $180 depending on the car model. Most people will be capable of replacing this part themselves. If you are just replacing the bulb, plan on spending less than $35. If you have to replace the whole light, including the cover, it can cost upwards of $100 to $300. However, if you want to hire a professional mechanic to install the tail light for you, the costs can go up.