CalDigit RAID Card - Manual (Page 26)

26 A. MacPro
(b) (8 Core MacPro) Remove the CPI cover by pulling the bottom edge of
the CPI cover slightly toward you.
1.8 Remove the fan module
(a) (4 Core MacPro) Remove the fan module screw and take out the fan
module.
(b) (8 Core MacPro) Remove the fan module screws (one at the upper-right
rear corner and a second at the lower-right front corner and take out
the fan module).
CPU Cover
Pull from here.
Fan module