Copy the address you want to withdraw to. If you don't have a VEO address you can create one following the Create VEO Wallet tutorial.
Go to your withdraw page.
Paste your VEO public address to the VEO address field.
Enter the VEO amount you want to withdraw.
Wait for a few hours. Your VEO will be transacted in the next block. You could check your withdraw status from Veoscan.
You could confirm that the transaction is in the mempool by following the directions in Deposit VEO.