unscrew them that will permit the tray to model there use to hold the tray in place. did you read the case manual on how to do it ?
I looked at the link you provided me and there's no screws on my case. It's just the tray and yes, I did read the manual. It tells me to put the hard drive on the tray, and then put it back into the case from the front of the case. As you know there are two screws on each side of the hard drive tray, these are the things that are blocking the way. I'm new to building computers so I won't know much.