You need a program for decompressing the files in the content file and once you have decompress them into png and the you just modify ir with paint or other program
Unfortunately this mod doesn't work 100% with the current version of SDV (1.11) I'm not totally sure but I believe it has to do with the cursor file. The mount will show up in game and work properly, but there are a few missing default game textures. The ones I've noticed are the farm preview icons when creating a game, and the + and - buttons everywhere (in the options menu, the zoom buttons if you have those turned on) Any chance for an update? The little guy is so cute
I don't know if onliy I have this bug but I think you made a mistake a the Cursor file i fixed it because the numbers were missing