OK, so I figured out how to change these Reactions however, there really should be an easier way of just changing them within Studio somehow. 

I am NOT recommending doing this as you will need to change a core icon.css file and it will get overwritten by any updates to Font Awesome. However, if you want to do this, this is what I did to change them. 

As I mentioned above, these are located in the modules/boonex/fontawesome/template/css/icons.css file. I would make a backup of this file first. I tried to put these changes in my Custom Styles area but it didn't work. You will need to download whatever emojis you want to use for you reactions. I changed all of my sizes to 20px x 20px as it seems to "fit" a little better. 

From there, I created a folder called "emoji" in the modules/boonex/fontawesome/template/css/ directory. I uploaded these emojis into that folder. Then you will need to locate the following entries in modules/boonex/fontawesome/template/css/icons.css for each reactions (I put names to them so you know what they are like haha, love, etc):

HAHA/LOL
.sys-icon.grin-squint:before, .fa-grin-squint:before

LOVE
.sys-icon.heart:before, .fa-heart:before

SAD
.sys-icon.sad-tear:before, .fa-sad-tear:before

ANGRY
.sys-icon.angry:before, .fa-angry:before

LIKE
.sys-icon.thumbs-up:before, .fa-thumbs-up:before

Each one of these entries have a "content" entry like this:

.sys-icon.sad-tear:before, .fa-sad-tear:before {
content: "\f5b4"; }

You will need to change that "content" to point to the folder you uploaded your emojis in :

Change from:

.sys-icon.sad-tear:before, .fa-sad-tear:before {
content: "\f5b4"; }

TO (assuming you named your sad emoji as sad.png)

.sys-icon.sad-tear:before, .fa-sad-tear:before {
content: url("emoji/sad.png"); }

Keep replacing each one above with  url("emoji/xxxx.png"); xxxx = the file name of the emoji

You're welcome 😀