Switch off your phone.

Use an iOpener to loosen the adhesive beneath the rear glass. Apply the iOpener for at least two minutes. You might want to repeat this step several times during the back cover removal.

The adhesive of the Samsung Galaxy S9 Plus is very strong. A hair dryer, heat gun, or hot plate may also be used if you aren't able to open the device with the iOpener. Be careful not to overheat the phone—the AMOLED display and internal battery are both susceptible to heat damage.