Understanding stand removal of iMac

The only access to the hinge is from the inside of the case.

Plus then you will need a VESA mount bracket to replace the stand.

We can not post links to tare downs here in this community.

So you'll have to do some web-searching on your own.

The other option, is to just attach a VESA mount adapter on the existing stand.

https://www.amazon.com/VIVO-Adapter-Bracket-Computer-Stand-MACB/dp/B00RW9F336/ref=sr_1_4?

I had this same question last month on 2019 iMac -- I wanted to move the stand on an i3 iMac over to a i5 unit that had a VESA mount -- I didn't want the VESA mount, but I wanted its i5, flash SSD, 32gb RAM internals

I read a lot of CONFUSING tutorials saying removing the stand was easy with a plastic card -- only a couple people noted that 2012 and newer don't work that way like previous hardware -- you had to get the Apple VESA mount when you ordered your 2012-2019 iMac -- I am not sure if the Apple VESA hardware can be installed later without removing the main board (a complete disassembly like in your photo)...

I had both my stand and VESA machines apart side by side -- looking at the nuts and bolts, the tension springs like in your photo -- considering swapping the VESA parts with the stand -- looked too complicated for me and requires at least one rare special order tool

I ended up just swapping the VESA i5 internals over to the i3 iMac -- making an i5 unit with a stand from the i3 machine

now the i3 vesa machine is parts -- 2019 21.5" body with original VESA mount installed...

+++++

like den.thed wrote: use a VESA mount adapter on the existing stand is one option

No way that I know of but if your goal is to attach another mount the following may help (and the fact that this product exists may also give an idea of the ability to remove the original stand). https://vivo-us.com/products/mount-macm1?_pos=1&_sid=4b9321628&_ss=r