A cut phoneline can be repaired in a minute or two.
It doesn’t take a McGyver, it just takes an older person who is familiar with repairing things.
Honestly, I wouldn’t know where to start. Green-to-Green and Red-to-Red? Or vice versa?
Of course if they had VOIP, it’s an entirely different matter. Orange-to-Orange/White Stripe? It’s all so confusing.
I’m pretty sure you still need McGyver and belly button lint.