How do you motivate an individual Soldier with low moral?

Motivating the "un-motivated" really comes down to that individual person. Some Soldiers will respond to one thing but not others. For some, all they need is to be taken aside and be told to straighten up while others will only respond to counseling statements and things like that. I think sometimes,we as leaders fall into the trap of thinking that since one thing worked for Soldier A it will work for Soldier B.

A significant emotional event.

folks, this is where NCO's assist their battle buddies, and do not leave him/her behind. You need to have their six, because, someday, you just might need them to have your 6.

So, when I was unmotivated on a run would say "Sound off! We need some motivation! False motivation is motivation nonetheless!"
Later on, when I was an NCO, I asked myself "What leader inspires false motivation?"
Then, a stripe later I realized that there are those who are just not motivated by the service. They make great E-4s all the way up to RCP as long as they keep their nose clean.

I've run into this a few times - they can be difficult to work with, but what I found worked best is to ask the SM what brought them into the service to begin with - and work from there. Often, I found they lost sight of the initial motivation that brought them to the recruiting office in the first place and once they realize it again, they change and get RE-motivated.

Oh good question here. As a old Soldier myself we had corrective actions that would motivate them ASAP School of Soldiers, CCF. If a Soldier can not be motivated then there are no incentives. But first he needs to be counseled and find out what is the issue ( If any) give him some small tasks and be vigilant correct when needed but most of all praise him for doing a great job. You wont believe how much it means to a soldier when you praise him in front of his peers it makes him/her feel appreciated but most of all part of the TEAM.