seems a daunting task mate but not really that hard at all,are you fitting the turbo engine to another cabby or a tintop
was doing this the other day as i am converting my cabby to efi,had the loom out and the new loom laid in in about 3 hours
i usually just unplug all the bits like leccy windows central locking leccy mirrors if fitted and just leave them there and plug them back into the new loom,allthe plugs are different shapes you cant go wrong with it.
if you were up my way would do it for you for a small fee lol