IBM RT PC Options Installation page 107

10. Turn the diskette drive lever counterclockwise to open it and
remove the shipping card, if one is present.
11. Replace the cooling fan assembly. See "Cooling Fan Replacement"
on page 2-6.
12. You have finished installing the drives. If there are other options
to be installed, do so now, and then check out the system again,
using Section 9, "Checking Out the Option Installation" on page
9-1.
Section 2. Removing and Installing Drives in IBM 6150 2-63