Clean the subflooring and unroll the carpet. Allow the carpet to expand for at least an hour to overnight. Allow 6 inches of carpet to curl up the walls. Press the carpet next to the walls.
Flip the carpet over and with a piece of chalk indicate the straight line where the carpet meets the wall. Use a utility knife to make your straight vertical cuts. Cut the corners into V shapes. Place heavy objects like paint cans around the perimeter to hold the carpet down.
Overlap by 2 inches carpet to create seams. With a utility knife cut through both pieces of carpet. Weigh down the other section of the carpet.
Spread adhesive glue on the subflooring. Press the perimeters of the carpet on the first piece of carpet that was laid down. Use a carpet roller to press the carpet onto the glue.
Apply seam adhesive to the seams. Butt both pieces of carpet together. Roll the carpet roller over the seams. Finish gluing the other side of the carpet and rolling into the glue.