First: Make some very chocolatey chocolate milk
Then, take some ice cream (either vanilla or chocolate, depending on how X-TREME you want your milkshake to be) and melt it in the microwave
Now, just pour your chocolatey chocolate milk into the bowl with the melted ice cream and WHISK WHISK WHISK
Finally, pour your milkshake mixture into a glass, add a straw and
BOOM! MILKSHAKE ACCOMPLISHED!