Original sentence: The three channel(BBC HD, ITV1 HD, Channel 4 HD), 720-line Freeview HD service will start on 2 December 2009 and will operate on multiplex BBCB (aka B or PSB3) from that date in regions that switched-over on or after that date (plus Crystal Palace), with the service coming to switched-already regions 12 months after the switch date - in 2010 Wenvoe, Mendip and Durris all all their relays will have a free HD service.This means in 2010, Stockland Hill, Calbeck, Caradon Hill will have switched in 2009, so they get the HD service one year from the last day of the switchover
Edited sentence: The three channel (BBC HD, ITV1 HD & Channel 4 HD), 720-line Freeview HD service will start on 2 December 2009 and will operate on multiplex BBCB aka (B or PSB3) from that date in regions that switched-over on or after that date plus Crystal Palace (London), with the service coming to switched-already regions 12 months after the switch date - in 2010 Wenvoe, Mendip and Durris and all their relays will have the Freeview HD service.This means that in 2010, Stockland Hill, Calbeck, Caradon Hill (switched in 2009) will get the HD service one year from the last day of the switchover