I'm guessing your partition information is from GParted that you ran and it was from your HDD . . . which means your / was mounted.
You CANNOT manipulate partitions when they are mounted. GParted won't let you do that and that's why you're seeing things grayed out.
The way to do this is with GParted ON A LIVECD.
But before you try this, read these articles: here and here. Also read this thread.
Tip1: Resizing can be risky. If you end up borking things and get bumped out to a maintenance shell (CLI ONLY), try this command: sudo resize2fs -f /dev/<your partition - sda1, whatever>. That command is particularly useful if, after running fsck in the maintenance shell, you see the message "Either the superblock or the partition table is likely to be corrupt".
Tip2: BEFORE you put your seat belt on and try this partitioning, backup, backup, backup! Whatever docs, spreadsheets, music, images/photos, etc., you value, make sure and put copies of them on removable media (like a USB stick.) AND, if you have your passwords in some sort of db (like KeePassX uses a .kdb file), put a copy of that on removable media too.
Tip3: Linux is especially sensitive to command line syntax. If you miss a space, do uppercase instead of lower case, put in a non-existent switch, need to be sudo, whatever, you will make the CLI cranky and likely get a message like, "cannot find command", or "This program can be run only by the system administrator", or something else cryptic and nasty. If you get one of these messages, go back over what you typed on the command line and you either mis-spelled something, left out a space/put in too many spaces, forgot to precede the command by sudo . . . which means super-user or administrator . . . etc.)