You have to add or subtract oil from both fork tubes. You cant just take off the cap(or shouldn't) because there is a lock nut on the under side and there is a specfic measurement for lock nut to cap.You have to remove the front wheel take the cap loose while the slider part spins and the cap will come loose. But it will still be attached to the rod inside. Then u can deal with the oil. You need a service manual there are measurements as to what amount of oil is in each fork tube. Just make sure there is no weight on the forks. You may need to change fork springs.