Deadalus 2.5.0-ITN1

In Deadalus 2.5.0-ITN1, how can I transfer back my ADA from its “Rewards wallet” into its “Balance wallet”?
It is impossible to do this by any means.
Please consider that the “Rewards wallet” has 15 word recovery phrase, whereas the balance has 12.
I already managed to redeem my rewards into the main net. But I can not find a way how to send out my invested ADA existing in the “Rewards wallet”. Can anybody provide me with some knowledge and help about it?