Change/remove "usually ready in xx time" from Craft checkout

[jackp]

I want to use Shopify's built in 'this location offers pick up' feature but it forces me to select a time, such as "usually ready in 24 hours". I want to either remove it completely or change the time to something suitable for my needs which can vary from 2-10 weeks. 5+ days is misleading for customers. I have trawled through the code and can't find how to modify this in the checkout page specifically.

Currently I have a free delivery option labelled as collection and have to email the customers after they have ordered with the collection details. This works but is clunky and the build in feature seems like it would work well, if it wasn't for this issue.