rbr750 network password chaange

> I would like to change the network password without changing it on
> every connected deice. Is that possible?

   Why?  Is there some actual problem which you are trying to solve?

   Sure you can, _if_ you change it (on the router) to what every
connected device is using.  You can't make a change on the router which
will also make a similar change on every connected device.