Hi Mussie,

You are lucky; the only guide I was able to find for your phone happens to be the one you need! Here are instructions showing you exactly how to replace the screen on your phone.

Xiaomi Mi 2 Screen Replacement Replacement - iFixit Repair Guide

A replacement screen is a little harder to find, as so many other versions come up, like for the Mi Mix 2 and the Mi A2, etc, but you should be able to find them on the major sites like Amazon, eBay and AliExpress. Here's one that came up for me on a cursory search.

Xiaomi Mi2, Mi2S LCD Screen and Digitizer Assembly Black - ETrade Supply