How to update address for less active member that is not in our ward?

A member of my ward gave me an updated address for her inactive (adult) child. This inactive member's record is not in my ward and presumably was in the ward where he was living prior to moving to a new address, which is the updated address the ward member has given to me.

Is there any way I can update the address remotely? It occurs to me that I could move the inactive member's record to my ward, update the address and then move it to the new ward, but this doesn't seem like the most accurate way to do things as far as record-keeping is concerned. What can I do?

I'd use maps.lds.org to locate what ward they're in and use CDOL to locate the ward clerk's contact info and forward the information. I wouldn't try to update the address directly. Moving the record will erase any existing HT/VT assignments.

I have done this in the past using an MLS message to Membership Support (this was in the days before Leader and Clerk resources). I sent a message with the information for our member (full name, birth date, membership number) along with their child's information (full name and birth date) and their new address. I mentioned the child was not in our ward, but their parent wanted to make sure their record was moved to the correct ward as they were not active in the church.

I received a nice reply that they had moved the child's record to their correct unit. I would assume that if it is just an address change without a ward move, the HT/VT information would remain intact this way. In my case it was a different part of the country so that didn't matter but I did not want to erase the prior ward information for them by pulling them into our ward first.