I don't think there's a way to do this. It would be a security vulnerability if you could change network settings remotely without authentication. Perhaps if you have an authentication URL configured, you could post some query to change it, but I dont know of any, and that's going to take longer to figure out than having someone at the site make the changes.
The easiest thing is going to be to train someone at the site on how to hit the check mark box, hit hit network settings, and '**#', then go to IPv4 settings and set DHCP enabled to Yes. You don't need a technical person to follow simple directions on a phone UI.
Or if you want to do factory defaults, train them how to hold #, plug the cable in, and hit 123456789*0#. That shouldn't be difficult for end users to follow. You could even take screenshots on the setting screens and make a document for them.
