The "disk" (it's really a small lever attached to your hood latch release knob) should be pushed aside by the conical bottom end of the vertical post attached to the hood.
If it's not moving the disk/lever aside, gently lower the hood and see if the bottom of the cone is centered on the hole in the latch. There is a small collar around the hole to guide the hood post into the latch and the cone pushes the lever aside until it passes through and then the lever holds the post/hood down. Make sure it is centered on that hole, front/back and left/right before you continue. It could have been a little off at assembly or moved after completion. The hood pin can usually move a few millimeters in any direction to allow you to center it.
Lubricate the conical end of the hood post with white lithium grease (same thing used for trailer hitch balls, available at any auto parts store, Walmart, Home Depot, etc) and lube the latch lever surface where it strikes the hood post as well and, as a precaution, apply a little oil to the latch lever pivot point to insure that it's moving freely.
Now that you've done all that, pull the emergency catch and the hood post should fit into the latch. Scope it out to make sure it is passing straight into the latch, then gently push down on the hood from the outside and, placing both hands flat against the bottom 12" of the hood, straighten your arms and push straight down with your body weight and it should latch it down. If not, then the hood post is too close to the hood and should be adjusted down with the two nuts at the top of the post inside of the hood. Adjust it down one turn at a time until you see/feel it latch firmly in place. You can tell you're in the right spot when you feel it latch and the hood surface and the body surfaces match height.
Hope this helps!
