Grab the main page with all the links:
curl https://slackmojis.com/ > emoji

Open file in vim and run the following commands:

v/src=/d
%s/^.*http:/http:/g"
%s/?.*$//g

This deletes any line that doesn't start with src, deletes everything before http:, and delets anything after ?.

Now loop over each URL and download the image:

while read emoji; do   
  curl -O $emoji; 
done <../emoji

Install Slack Emoji Tools Chrome extension.

Drag all your emoji into the bulk upload box and then flip your machine over and fry some 🥓, cuz it's gonna get hot!