How to write a character watching a video of himself in first person?

Hi Starrystorm, this sounds like a cool idea! It really depends on your writing style and what you feel most comfortable with, but I would guess that the real focus is on the narrator's reaction to the video. In that case, you need to show that by how the narrator is reacting, and embed the description in that. E.g. "trembling, I hit play. As Karen and I danced on the screen, tears welled in my eyes, as I realized that I would never hold her again." Option C sounds like it would emphasize a contrast between the narrator's present character and what they were like in the past, which might be nice if that is what you are going for; e.g. "I watched as video me dribbled down the court, leapt in the air, and effortlessly dunked the ball. The crowd rose as one and cheered. Present me looked down at the stumps of my legs and gripped the metal rims of my wheelchair."

On the other hand, if the video is conveying new information to the narrator, then you might want to convey that with more straightforward narration, though still keeping the reader in the narrator's state of mind- "On the screen, my car was approaching the intersection. The light was yellow but I accelerated. From the diagrams of the accident, I knew that the blue Toyota would appear any second. Suddenly, something caught my eye- there was an old man on the sidewalk getting ready to cross Holmes St. From where he was, he would have been able to see the whole collision that was about to unfold, so why hadn't he been mentioned in the police report?..."

(Sorry, couldn't help it)

Another option could be to have a scene break, and then have everything be from the perspective of the video, although then you lose the reaction of the present-day MC until the very end. I've seen italics work for this in the past, though it could be harder to read for extended stretches.

I'm kind of favoring a fifth option here myself. It's a bit like your option C but different--& easier to handle once you've set it up.

E) Put the actions of the "video me" in third-person.

This can work because, as you imply, this guy's not seeing the memories from his own POV as if he had a helmet-cam on him or something--he's actually seeing an image of himself doing the actions he did. So it's a little more separate, he's watching someone on the screen, even though that someone is him.

Here's an example of how I would set this up.

I activate the [whatever the system is], and the image comes up before my [eyes/mind's eye] crisp and clear. The man in the image looks [scared/happy/confused], and I remember that feeling as I look at this face that has my own eyes in it. He is me, and yet I'm watching him. He is [Character's Name].
[Character's Name] stands up and reaches for [thing,] and I [remember/feel whatever... the point is you can get both the image and the feeling into the same sentence if you want by using this technique!]

Are you emphasizing the emotions of the past or present MC?

If it's past MC, you might want to tell the scene in the form of a flashback. It would be more immediate to the reader.

If it's present MC, you might have to do more "telling" of the actions in the past and focus more on the character's reaction to what they're seeing.

Your character is watching a past video made of himself - correct?
I would write this just as I would if the character were watching someone else on the video. IMO it would be best to write this without much emotional interpretation by the character during the video - save that for before and after - otherwise the message on the video will get gummed up and be difficult to read.

Just my opinion of course, YMMV.