thanks for the responses. I'm having trouble with the front fan. The black screws aren't long enough to go through and the screws that come with the fan are too big for the case holes. As for now I used some of the extra scows that were long screwed them in from the back and let the fan hang on them. It really isn't that sturdy but for now its working. The zip tie idea does sound like it would work
The screws that work for the 200mm fan should have come with the case, in this picture you can see everything that comes with the 912.
The black screws on the left include some medium length and 4 long screws, the long ones are the ones you will need. If for some reason you don't have them, then zip ties will be your only solution. And trust me, if you install with the zip ties, it will work fine, that's how I installed mine, I found the long screws AFTER I had already used the zip ties.