Can a character of discharge from the USMC be changed from General to Honorable?

So what you really mean is that you took liberty, or a pass for us non Marine folks, WAY outside the liberty limits by several hundred miles and then didn't return till an unspecified amount of time later. I'm curious if you were also reported AWOL.
I agree with everyone else that there is more to this story. Not that I haven't seen commanders in the USMC do petty things like what you've said, you're just only providing the parts of the story that sound favorable to you and paint you in a positive light. For instance, you said you were being separated for a medical injury, but you were not separated by a Med Board or you wouldn't have received a GUH because the commander is not the separation authority for Med Board service members. It's not likely that you were actually outprocessing because who would let someone take a pass while they are clearing?

Too much doesn't add up. Good luck with getting your upgrade.

You have a post from a year ago. If you were a Marine, why is this not in your profile? Instead, you are listed as Army National Guard. Complete your profile and have it verified. You are not telling us all of the details because your story does not add up.

You were AWOL because you were not authorized to go all the way to NYC from North Carolina on liberty (600 miles). All Marines know to notify their leadership if they can not make formation.

I suspect their is more than the one incident. It is highly unlikely that the command gave you a discharge based on that one time for that matter even two or three times.

Non-judicial punishment is for minor offenses that require correction and does not warrant separation. If you served your punishment, you character of discharge should not change. Now with that being said, you must have done something that warranted the general discharge and I can promise you with certainty you are leaving out key details of this story.

I feel this is a generational issue more than anything else. As a Vietnam Vet, over the decades, it seems to me that our society (USA) as a whole simply is no longer what it used to be. A good example is Covid - 19. I lived the first 18 years of my life in a very tiny midwest farm town. Morality, decency, kindness, gentleness, were all extremely common practiced adjectives. The 'age of reason' was accepted without question for a chil'd 8th birthday, yet, today, aside from my two children I don't know a soul under the age of 50 who knows what the 'age of reason' means. All 50 states had Blue Laws, for example, in my state it was illegal for a man with a moustache to kiss a woman in public on a sidewalk. Most blue laws were absurd and a bit vindictive and when the Boomer generation got their law degrees they set out to rid each state of Blue Laws. Profanity was rare, the first time I ever heard the "F..." word I was 20 years old. It was not such a stretch of the imagination for young adults to comply with rules, regulations, policies, procedures, etc., and if you did something wrong the vast majority of people knew it and they accepted the consequences because they knew they deserved those consequences. Today, I would venture to say thapent only 30% of people under the age of 50 understand when they do something wrong and yet, 50% understand that they deserve the consequences of their mis-behavior. Rules and regulations are not written and implemented 'to be broken' and then, hence, 'to be argued to fill a void in your brain or your life'. They are there to protect you as much as to protect others. If you choose to live you live on the edge or to deliberately defy the United States societal norms, you do have other choices, such as; moving to another country, spending your life in prison, or merely suffering the consequences of your behavior. Have you done anything to redeem yourself to our society that entitles you to an upgrade? For example, have you perhaps donated a year of your time helping the needy, in any capacity? How can you prove that you are worthy of such an upgrade? You do not just deserve 'free' handouts.

If you are honestly looking for assistance you should provide the correct details up front. Too much about your story seems inconsistent. This is a great place to seek out advice, but you can't BS a group with a collective military history of over 1000 years.
Give us the whole story all at once and you will receive sound advice. Otherwise, don't bother.

The process used to be application/petition the Board for Correction of Naval Records (BCNR). It may have changed. They correct admin errors, but an application to upgrade must be fully warranted, based on the evidence provided. It must have merit.

SPC Kevin West
I don't see anything in your profile that suggest you were in the Corps. Is there more to your story?

"They" can't unilaterally change the nature of a discharge since it is a straight mathematical calculation of your average conduct mark. That said, you can still apply for modification.

Yes.
BREAK
No one here can help you if you're not going to be honest. No one get's a General characterization of service from one minor incident. There is clearly far more to his story than you're telling us, and those details can be the difference between success or failure in your efforts to change the characterization of your discharge.