When to change running shoes for the Comrades Marathon

Welcome to Ask Coach Parry. Today we chat more about changing shoes before the Comrades Marathon.

The question today is from someone who has just run a qualifier for the Comrades Marathon in their current pair of shoes and they think they may need to get a new pair.

When would be the best time to do this? When is too close to the Comrades Marathon, when is too late? What is the best way to go about it?