Let all the air pressure out of the fork, remove the valve core. To remove the new 2019 RockShox top caps you require a cassette lockring tool. Previous models use a 6 sided socket, like the Fox fork we’ve already been through. Remove the top cap, on the underside you will see some threads. Thread the spacers on to the top cap and do up snuggly to 2Nm with an 8mm Allen key. Remember to check the RockShox instructions to see how many will fit in your fork. Reinstall the top cap and tighten to 24Nm. After reinstalling the valve core, pump the fork back up as per the instructions and check the sag. You may need to make small adjustments to your settings after adding the volume spacers. Use your sag as a guide for air pressure.