What stands are these? Can you provide a link? Or illustrate what you are saying with pictures?

These are the official sonos one stands

the part im talking about is the square platform like part where the speaker actually sits.

Is the relative going to use them with their own Sonos One (or One SL)?  If so, just leave the power cord there and have them give you their power cord.

But if that’s not an option, below is the link to the user guide. It does appear that the two pieces just snap together, so removing them does seem like a challenge.  I would try and press down on the bottom piece (from where you can see it near the electrical plug) gently but firmly.  It looks like a friction fit, so you should be able to remove without breaking anything if you can get close to even pressure.

https://www.sonos.com/en-us/guides/one#to-sonos-one-stand-one

Im only giving the stands. 
I was trying to do what you just said but didnt want to force it in case it breaks..

just curious if anyone was actually able to do it , and/or anyone who actually broke it doing this way?

This is the manual for the stand: https://www.sonos.com/guides/one#to-sonos-one-stand-one. It seems when setting up the power cord should be put through the gap in the base. That would mean you also should be able to push it back through the gap.

Only the part of the cord that can go through the whole in the base is the part that connects to the speaker it self.  Unfortunately this is also stuck  through that part where the speakers sit on.

unless you can open them, you cannot remove the power cord from the base nor this platform

You should be able to separate the inner and outer part of the base, since they where united when assembling the base. Maybe with some prying: