Is it possible to upgrade my hard drive on my xbox one x to ssd

Not really...

Xbox Series X games / upgrades / updates has to be installed onto the Series X internal or expansion card SSD,

You can have Xbox One games on your external hard drive that will get an Series X upgrade but the games will need to be transferred to the Series X and then the Series X upgrade will need to be downloaded onto the Series X SSD,

As an example...

I have Marvel Avengers on my external hard drive that will get the Series X upgrade and I will transfer the game over to the Series X SSD ready to download and update the game to the Series X version when available.

You forgot the xbox one x used a ssd lol

There is no way that the One X uses an SSD...loading times for Forza Horizon 4: Up to 2 minutes to load on my One X vs around 30 seconds on my PC (admittedly has an M2 drive).

The hard drive in the One X is the: Seagate 2.5” hard drive, model ST1000LM035 which is a 5200rpm drive and is a mobile hard drive

https://www.gamersnexus.net/guides/3253-xbox-one-x-external-ssd-worth-it-game-load-times

An Xbox One model had a hybrid hard drive/SSD. Now currently the Xbox Series X|S only has a SSD drive in it.

If they do fix this problem it would be music to my ears I love my xbox one x but I just don't like the idea of using an external hard drive even though you can use a usb lead.i would ask someone who knows how to put an SSD hard drive inside my xbox one
x if I knew someone who could do it for me but I would find it hard to trust someone to get inside it to fit one in internally.i wouldn't mind if I could get maybe a three terabyte SSD hard drive in it.i wonder if Microsoft would do it for me I would be more
than happy to pay for this to be done at least my one x would be used to it's full potential.

I have a SSD in my Xbox One S currently. Would the upgrade to Xbox One X still make games load faster?