Transit fter market Immobiliser

[Julesd]

Hi averyone,
Hope someone can help me here please?
Long time since I fitted an alarm or immobiliser.
Someone has asked me to fit an immobiliser to a 2011 Transit.
He wants to make it more secure.
I still have some immobilisers here.
I suppose I need to cut the starter and the fuel shut off valve.
Has anyone got the location of the best place to pick for the cuts please?

Thanks.
Regards,
Jules.