Pull each rear-mounted storage drive out far enough to disengage if from
the disk backplane.
See Remove a Rear Storage Drive.
Note -
It is not necessary to completely remove the storage drives from the
server; simply pull them out far enough to disengage them from the disk
backplane. If you do remove the storage drives from the server, make a
note of their locations so that you can reinstall them in the same
locations.