In my MacBook Pro (15-inch, Mid 2012)
MBP 15.4/2.3/2X2GB/500/SD/GLSY
Part Number: MD103LL/A
the 3 screws in this step are hex screws
crwdns2858784:0crwdne2858784:0
crwdns2858785:0crwdne2858785:0
crwdns2858779:0crwdne2858779:0
In my MacBook Pro (15-inch, Mid 2012)
MBP 15.4/2.3/2X2GB/500/SD/GLSY
Part Number: MD103LL/A
the 3 screws in this step are hex screws