Tablet [Q] Cant Write to External Sd card

I have been trying for the past few days since last thursday actually. I have been trying to transfer about 14gigs of comics from my computer to my external sd card. Thing is i cant write to it. I decided to use BTsync in order to do so but, i cant write it from there either.

I am on a Galaxy Tab 2 10.1 running 4.2.2 running cyanogenmod .

Is there a waz that I can force the system to let me write to it. I donšt care how also i am also rooted. I dont care how please help me i have been trying for soo long. I am having withdrawl from Flash comics Please this is my first time here i need your help.

Also i was trying to install 4.4.2 from CWM it fails each time anz help would be appricated.