現地の携帯電話を使えるようにする方法を教えてほしいって英語でなんて言うの？

If you are in a different place then you could use the terms 'locally' or 'here' this would suggest that you don't know what to do for that area
'can you tell me' suggests they would verbally tell you what to do
'can you show me' suggests they would physcally show you how to do it
By asking 'is there anything i need to do' explains you are not sure how to work it and need help

"Can you show me how to operate this phone, please?"

"Operate" and "utilize" are verbs that mean use

"Please show me how to utilize this phone."

As always, it is necessary to be very precise when asking for assistance to be sure that the answer to your question actually helps you. Your query seems to be about using a local mobile phone. Most phones are international and the functions do not change from country to country, although the language function can be changed if you elect to change it yourself using the settings on your phone. Above are listed 3 possible queries if you really need to know about using a mobile phone in a foreign country.
My guess is that you really want to know how the local sims work, so in that case please substitute 'mobile phone' with the word 'sim' in the above questions.

The first question "How do I get my mobile phone to work locally?" suggests that you already have a phone, you have gone to a new place, and you cannot get your phone to make phone calls (or some kind of function) now that you are in this area. You are asking them to advise you on how to fix this. The second question "How do I use this local phone?" suggests that you have got a new phone in this area and you are asking advice on the overall workings of the phone (for example, how to turn it on).

When you want to ask for help on how you can use a local mobile phone, then you may do so in the following ways:
-Can you please show me how to activate a local mobile phone?
-Please show me how to use a local mobile phone?