Re: I need help
Not overly familiar with Nikon as I shoot Canon, but the process should be the same. If you are in Manual mode (M), you will only be able to shoot at 30 seconds or less. It will be the same as any other photograph you shoot as you will press and release the shutter button one time. The shutter will remain open for the predetermined amount of time and close on its own. There is nothing special that you have to do in order to keep the shutter open.
Now, of you want a longer than 30 second exposure, you will have to switch into Bulb (B) mode. The shutter becomes controllable by the shutter release button, and will stay open as long as you have the button pressed. This is why the remote release is necessary in this mode. Otherwise you would have all sorts of camera shake from your hand.
What specifically is happening when you are pressing the shutter button? Is the camera firing, but not long enough? Is it firing, but the exposure is wrong? What is your exact issue other than it isn't working. You are also welcome to give me a call at 336-681-0220 and we can discuss it a little more in detail. I promise, long exposures are not difficult at all. They are quite fun in fact.