What this will do is mount /sdcard2 as /sdcard and your phone storage /sdcard, to /sdcard2. 

Okay, so I started playing around in the vold.fstab, thanks to some inspiration form this thread : http://forum.xda-developers.com/show….php?t=1625238,
and I managed to change to get the internal memory show as the external sdcard, and my 32GB sdcard to show as the phone storage. 

If you would like to try this, then use an app like root explorer and navigate to /system/etc and open up vold.fstab. 

You’ll see two lines:
dev_mount sdcard /mnt/sdcard emmc /devices/platform/msm_sdcc.1/mmc_host
dev_mount sdcard2 /mnt/sdcard/ext_sd auto /devices/platform/msm_sdcc.3/mmc_host

Change them to this:
dev_mount sdcard2 /mnt/sdcard/ext_sd emmc /devices/platform/msm_sdcc.1/mmc_host
dev_mount sdcard /mnt/sdcard auto /devices/platform/msm_sdcc.3/mmc_host

Then reboot. 

Both mount points are accessible through file explorers, and both are accessible using an MTP connection (Media Sync) when connecting to the computer.

Transfer from:http://forum.xda-developers.com/showthread.php?t=1716166