Hi [NAME],   Yes, you can safely remove the pin and install the 2.5" drive.   Generally, the mid-expansion bay can be installed with 3.5" drives and the pins are in place to connect to a 3.5" disk carrier.
Hello, I'm trying to install 4x 2.5" SAS drives in my R730XD server's mid expansion bay with 2.5" to 3.5" drive converters  but the screw hole isn't aligned with the pin on the drive converters. Can I safely remove the pin that work as a screw on the drive converters and it'll work? I think that it should work, I'm just asking if that pin was there to prevent using 2.5" drive in the mid bay for some reason. Thank you for helping me! [IMAGE]   [IMAGE]  
Installing 2.5" SAS drives in R730XD's mid expansion bay