I decided to test gate.io today. This is how you can withdraw your Grins using Grin++ on Windows, Linux and MacOS in 3 simple steps. First, open your Grin++ wallet and wait until your address is green like this:
Now, go to Gate.io, click on WITHDRAW; put amount, your address and the rest of the information:
Click on Submit request and wait few seconds.
Money! 
Done. What were you expecting?! It is that easy 
EDIT: Gate.io REQUIRES KYC.
What about other exchanges? Deposit and Withdrawal transactions are still very difficult
Bitforex works exactly the same way @GrinVN
All you need is SMS verification and 2 Factor Authentication.
On BitForex account verification (KYC) is not always mandatory. It is necessary to go through it only to withdraw from the account of Chinese yuan (CNY) or if your daily withdraw is over 100btc. The first exchange I made for Grin was on bitforex. I still use it sometimes. I asked them today (live chat) and Slatepack expected in 3 days!!! 
Bitforex implementing Slatepacks would be really great!!
So many exchange are now starting to support Grin, Grin as a project is going great 
Here we go
gate.io exchange increased GRIN withdrawal transaction price from 0.1 GRINs to 5.3 GRINs. It is an insane 5300% withdrawal price increase.
