If this is a singular occurrence, you have two options: either have a garage release the fasteners and then you can retighten them using your own tool, or get a long breaker bar for your socket. If you want an impact driver, you may get ones specifically engineered to withstand forceful blows from a substantial hammer. In order to avoid potential splitting, it is necessary to use the appropriate impact socket size, since normal sockets are not suitable for this task.