i am a phone repairer and I have a problem. how do I deactivate mobile phone?

[ojie]

I am a phone repairer and i have this problem which i have been battling with of recent. please how can i deactivate a mobile phone?
your assistance will be highly regarded.
thanks Ramsey

[mobileman]

Hi Ojle. What do you mean by 'deactivate'. Please let me know so that I can reply you in a better way.

[BSalcido]

Can you please clarify «deactivate». I can’t get it.