Remove External Hard Drive partition, keep files?

Hey, is there any way to remove a partition on my external hard drive without completely wiping all my films on the other partition?

It is currently partitioned in two.

The partition I want to remove is MS-DOT (FAT) and the partition I want to keep is Mac OS Extended (Journaled).

In Disk Utility when I've tried to remove the partition the minus sign is greyed out and it says

I'd appreciated any help. Thank you.