The easiest way to do this, is using command line(terminal).
- First find the disk: diskutil list
e.g
/dev/disk3 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *X TB disk4
1: Microsoft Basic Data easystore X TB disk4s1 - Now earse
diskutil eraseDisk FILE_SYSTEM DISK_NAME DISK_IDENTIFIER
Replace FILE_SYSTEM, DISK_NAME,DISK_IDENTIFIER.
e.g diskutil eraseDisk ExFAT ABC /dev/disk4;