EMS could have been simple to obtain.

[KidGamer65]

because it s not about switching eyes its about fusing 4 eyes to make ems

In the manga it clearly says transplant so there is no reason to say its a fusion.

 

[SmartNoob]

My thread from Mar 2011

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I had come to the same conclusion but was proven otherwise :shrug:
read below

Spoiler

If all you have to do for ems is take your brothers ms and if both madara and izuna had ms why didn't they simply exchange with each other why did izuna have to go blind/die?

Because the EMS is the combination of two MS.

hmm so they eyes are not replaced by your brothers but added to them?

We dont know the process so no one can tell you. If its replacing then imo madara didnt know about EMS because he was the first person to achieve and it wasnt on purpose. His plan was to replace his MS with izunas but after he took it he realised it becomes a EMS and it grants the user another power that hasnt been revealed yet in the manga.

No you need both sets of eyes to achieve EMS, you can't just swap...
With EMS this demon like figure has 2 pairs of eyes

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While with MS alone he only has one pair

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Now something that would be possible is what if they each traded one eye? so that both of them would awaken the EMS in one eye... the missing one, don't know replace it with something lol xd