Cut a tenon on both ends of the cylinder with a 1/4” parting tool to. Size the tenons to fit your 4-jaw chuck. One tenon will be used to hold the lid in the chuck; the other tenon will hold the base.
TIP: I always taper these tenons just a hair, creating a dovetail shape. This provides a better gripping surface for the four-jaw chuck.
Remove the blank from the lathe and replace the drive center with a four-jaw chuck. Mount the stock in the chuck. Even though the four-jaw chuck can support the piece by itself, I always bring the tailstock up for extra support whenever possible.
Separate the top (lid) from the bottom (base) with a narrow, 1/16” parting tool. The narrow kerf helps maintain grain continuity on the piece. As you get close to the end, slow the lathe down and lightly hold the base in place as it separates from the top. You don’t want it to spin off the lathe and get damaged. Turn the lathe off keeping the base in place with your hand until it stops. Remove the base.