Mine are staying there but my friend wants to sell me his and he can not get them out of stake
When they just staked (when you got reward) you need to wait 1200 confs for them to become mature.
So there's nothing "your friend" can do except wait for them to become spendable again. If you want to disable staking, start the client with -staking=0
@dev: you mentioned before you might reduce the mature-time after PoW is over. I think you should do it.
1200 confs is way too long, especially since the confs seem to take quite a bit longer with PoS.