Change sim preference to call particular person in Dual sim I recently changed the second sim and I want that second sim to call for the particular person by default, previously I have set the first sim to do that action, 

Now I want to set those settings to changed or at least to be set to default,like asking every time which sim to call,

I cleared data in both phone and dialer app in settings of app management, but still nothing happened, the set default button is greyed out on both apps

Does any one know how to change the sim preference settings to call a particular person?
Found the answer by myself at last,

when you call that person there will be a change sim option in the top right hand screen, by choosing that we can change the sim preference and also the next time we call that person phone will ask for which sim to call.