Here's my abridged version from a developer's perspective:
create sequence 'multicam'
foreach camera source
{
import source to bin
create sequence
add video to sequence
add sequence to 'multicam'
}
create sequence 'final'
add 'multicam' to 'final'
right click 'final' sequence, select multi-camera and enable
Note that video track #1 will, by default, be used as the audio source. You can of course swap around afterwards.