I thought you had a sense of humour when you asked if they used magic, apparently it disappeared when you realised you can't count... or tell the difference between two obviously different companies and now suddenly its pedantry
I have a slightly unfair advantage here, I had some involvement in TW/VM's policies in a former life, in fact most of the policies VM have were largely based on TW policies/process pre merger, it turned out it wasn't only NTL's billing system that wasn't fit for purpose 
The first change we had to push through was a revised process changed policy as NTL wanted 6 weeks notice to brief out any changes to the call script, even for something as simple as checking serviceability with customers moving to a TW area.Anyway for clarity a large number of properties have cable and ducting in the street right up to the property exterior wall, eg those that have had historic service (you'll know because the account number will end 02 or higher), they should need a 1 man team and 30ish minutes to install 'on the day' though that can vary by area, an un-cabled property will usually have a pre-pull done with a two man crew prior to the install, paving/block paving/tarmac will not be lifted or reinstated, if a customer insists on a route that requires this they are told to lift and re-instate the paving and that any faults resulting/requiring further removal of the cable would be down to them to do the same again. More often than not cable can be taken round the edge of a boundary etc. as it's the easier option, though in a garden homeowners may be given the option of a 2" wide trench sunk 6" deep and conduit used. No pole work, magic or time machines and op wouldn't usually have to 'do' anything at that stage unless they insisted on a more complex install (it happens).
After that it's just swapping a router over, if your existing router supports ethernet WAN, you can drop the SH into modem mode in about 90 secs, if not changing the SSID and wireless password takes about the same and they then have 30 days to decide if they want to continue, that also happens to be the amount of notice the current ISP will ask for if they are out of contract.
