And replacing those images with a link to a custom ( or even local ) image.
If you’re using some kind of irc and want to parse chat;
I think the best bet is going to twitchemotes.com
and downloading the emote files from their API, to get all emote “text” - and replacing those with an image.
You should use emoticon_images instead of the old emoticons endpoint and http://static-cdn.jtvnw.net/emoticons/v1/:id/:size for the image URL. ID from the API and size either 1.0 for 28x28, 2.0 for 56x56 or 3.0 for 112x112 version.