Determine the source of the wrinkle. If the linoleum floor is newly installed, contact the installer to examine it as the wrinkle could be caused by poor installation or an uneven subfloor.
Apply heat using a hair dryer on the low setting. Heat the area until the wrinkled area feels warm and pliable.
Use a floor roller to smooth the area. Rollers can be rented from hardware stores or other places that rent equipment. A 75- to 100-pound roller is recommended for linoleum. Work from the wrinkle outwards in all directions to distribute the air pocket.
Lay a heavy board over the area immediately. Add bricks or other heavy objects on top of the board to put weight on the area and encourage the linoleum to remain flattened.