Firstly install the needed software:
core:~# apt-get install hfsprogs

List the target disk:

core:~# fdisk -l /dev/uba

WARNING: GPT (GUID Partition Table) detected on '/dev/uba'! The util fdisk doesn't support GPT. Use GNU Parted.

Disk /dev/uba: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x366ade79

   Device Boot      Start         End      Blocks   Id  System
/dev/uba1               1          26      204819+  ee  GPT
/dev/uba2   *          26       12139    97294336    7  HPFS/NTFS
/dev/uba3           12200       38897   214448008   af  HFS / HFS+

Mount the target partition:
core:~# mount -t hfsplus -o rw,force /dev/uba3 /mnt/mac/

if it was mounted automatically, umount and mount it back:
core:~# mount -o remount,rw,force /mnt/mac/

Test if you can write to it (we will just create an empty file with touch command):

core:~# df -h /mnt/mac/
Filesystem            Size  Used Avail Use% Mounted on
/dev/uba3             205G  113G   93G  55% /mnt/mac
core:~# touch /mnt/mac/testfile
core:~# ls -la /mnt/mac/testfile
-rw-r--r-- 1 root root 0 Nov 10 19:50 /mnt/mac/testfile