i assume you are trying to download the game, soo ill break it down for you kinda easier:
first you need to download deltapatcher, version doesnt matter.
second you need to download the file and extract it into folder you gona make/create, you also need to create folder for original SJM files/sprites
you need to extract the files trough 7-zip which is .rar extractor, you will need to find folder where gona mod files be, once its there you put or copy original sprites, sounds and etc into folder for original game, after that not much gona be left to do.
find .xdelta file in mod folder, then use the deltapatcher and use it on .exe game (the one in your steamapps folder), then you will need to replace game files with mod files and then its done.
if you DIDNT save the original files its fine, you can just redownload the game from steam, it should get rid of modded game and sprites.
if you talking about bug fixes page, well its supposted to be that way with saying a few things or soo