Mazda 2015 5 Owner's Manual page 312

In Case of an Emergency
Flat Tire
2. Open and fold back the trunk board
over the third-row seatback.
Trunk board
3. Remove the cargo sub-compartment.
Cargo sub-
compartment
4. Turn the tire hold-down bolt
counterclockwise with the lug wrench.
7-6
To secure the spare tire
Perform the removal procedure in reverse.