I would also say Kraken is the way you could sell bitcoin quickly you can sell $500,000 a month when you verity your account to Level 4
But also, they can freeze account at anytime and then good luck getting a-hold of them lol.
I would probably do it on Coinbase, a verified account can do $20,000 a day, so just transfer 20k a day and withdraw it every day
Thanks everyone for the advice.Contact Gemini or other for big exchanges private deal should be the best idea so far,
because I can't even get verified account on these exchanges,they only allow US citizen.
Best of luck going forward, would you consider selling small amounts to us in the mean time