Remove Key from Entity in MS CRM Online 365

Hi All,

I am facing one issue in my production environment.I have created one key for Lead entity and the key is a part of managed solution.

Now due to some customer requirement i want to delete that key but system is not allowing me to change key properties as it is a part of managed solution.

Can anyone suggest how i can remove that key?

Is there any code to delete code using SDK messages?

Thanks in advance.