The driver is legally considered a licensee, not a tenant. Because there was no agreement to pay rent and the property was given out of pure goodwill, no tenancy was created.
A license is a permission to occupy premises for a specific purpose. Once that permission is revoked by the owner, the driver's continued stay becomes illegal, making him a trespasser. He does not enjoy the legal protections given to tenants under rent control or eviction laws.
Before approaching the court, your neighbour should have a lawyer draft and send a formal Legal Notice for Revocation of License and Vacating the Premises.
If the driver ignores the notice, your neighbour will need to file a civil lawsuit in the local court for the following reliefs:
Mandatory Injunction: A court order directing the driver to remove his belongings and vacate the premises.
Recovery of Possession: To legally hand the physical property back to the owner.
Damages/Mesne Profits: To charge the driver for every day he illegally occupies the garage past the notice deadline.
Your neighbour must absolutely avoid trying to physically lock the driver out, cut off the electricity, or throw his belongings onto the street by force. In many legal jurisdictions, even a trespasser cannot be dispossessed without "due process of law.
Your neighbour should consult a local property lawyer immediately to issue the formal notice, as setting the exact legal tone early on is the fastest way to resolve this.
