Upgraded from M250 to Gig

Hi I was wondering if someone can help me please. 

via my online account I’ve upgraded from m250 to gig broadband. I’ve received all the contractual documentation confirming pricing etc. I’ve also received a confirmation email with an order number on. 

it does not mention anywhere in this documentation when the new speed will be added, is it over the air, does it need an engineer. The documentation is pretty useless in that regard. 

is anyone able to tell me please how the upgrade is done? How long will it take for the new speed to reflect. I already have a hub 5 so I don’t think I I need any new equipment. 

any help will be greatly appreciated. Thanks