Abusing Trust Boundaries for RCE

I'm a bit stuck on this one as I'm not that familiar with Git and all the associated terminology. 

How do I clone the repo?
which dir does the .mcp.json file sit in?
Does this not pre-exist as its adding extra capabilities\extension to the original code? 
Does the target host pull the file automatically to give me a shell? 

Many thanks - Gus