Remove all furniture and accessories from your bedroom floor.
Clean your carpet thoroughly before you begin, to avoid uneven color distribution. Allow time to dry before applying dye.
Purchase a professional looking carpet dye from a flooring or hardware store.
Rent a carpet shampooing machine with nylon bristles that can also be used to dye carpets.
Follow the manufacturer's instructions for use and apply carpet dye on a sample piece of carpet. Move the machine in an even motion, similar to mowing your lawn.
When you are happy with the color distribution, apply it on your bedroom carpet.