Dislocker - a Linux or Mac OS X computer forensics tool to read/write Bitlocker encrypted partitions, it can be used with FUSE (Filesystem in Userspace), a loadable Unix Kernel module, or without it, once the partition has been decrypted you can mount it as NTFS and read, write or copy everything. Note that this is not a brute force mechanism or hack; the user still needs to provide a recovery key or user password for the decryption.
However, dislocker is a command tool, if you are not computer savvy, it is very complex for you who don't have enough computer knowledge, but there is a dislocker alternative: M3 Bitlocker Loader for Mac, it provides easy-to-use UI makes operations very simple under macOS 10.13 (High Sierra), 10.12 (Sierra) and Mac OSX 10.11/10.10/10.9/10.8/10.7.
Free download dislocker alternative tool: M3 Bitlocker Loader for Mac now to read/write Bitlocker encrypted external hard drive and USB flash drive under Mac computer.
Tutorial to read/access/mount Bitlocker encrypted volume under Mac with M3 Bitlocker Loader for Mac
Step 1: Download and follow the installation wizard to install M3 Bitlocker Loader for Mac in Mac computer.
Step 2: Launch M3 Bitlocker Loader for Mac, insert Bitlocker encrypted external hard drive or USB flash drive.
Step 3:Select Bitlocker encrypted volume and then click "Open" icon to continue.
Step 3: Enter the password (or 48-digit recovery key).
And then click "Unlock" to unlock Bitlocker encrypted volume.
Step 4: After decrypting, the Bitlocker encrypted drive will be mounted to a regular drive with read-write access support.