Re: Help: Understanding partitions and editing/resizing them
You certainly need to boot from a live CD to start messing with moving partitions. Also the thing to remember is that it's dangerous, a mistake can be very costly. I would see it as essential to buy or borrow a usb drive and make backups on that. It's always a good idea to have backups off the machine anyway, backups on the machine don't protect you from losing the whole thing.
You have a huge spare space in /dev/sda5, the system partition is not going to get much bigger, you could keep 13 GB for that and then make another partition of 148GB. You could mount that so that it is accessible from /home/userxx, perhaps on a directory /home/userxx/additions.
Couple of other things, if you format a partition ntfs it can be accessed by both Windows and Ubunu, could be useful?
And to tell people about your setup the usual way is to send the output of "sudo fdisk -l", with an el, not a one.
ubuntu 14.04 with full encryption, an SSD and dual monitors