There are a lot of ways to wake up during the night for DEILD. You can try autosuggestion. "I will wake up after every dream." That works so well for me that I often wake up and remember some non-REM dreams! LOL! Try it for a few weeks. If you don't have any luck with it by then you can keep at it, try another way to wake up (suggestion below), or give up on DEILD. If you are really tired there is a really good chance that no matter what you do you won't wake up during the night.

Besides an alarm clock you can try:
cell phone on vibrate alarm in your pillow
sorry, I can't seem to think of any more right now. There may be other ideas in the DEILD tut here.

With dream journaling in the night you have a few choices when it comes to DEILD. If you wake up and you didn't just have a dream then DJ away, cause you can't DEILD then any way. You can try a MILD afterward if you want.
If you did just have a dream and you want to DEILD decide if the dream you just had is worth remembering. This is especially important if you are going for a DEILD chain of LDs. If you MUST remember it then just write it down and go back to sleep. You'll get another chance to DEILD. If you can deal with possibly losing memory of it, just run over it in your mind a couple of times, then DEILD. You might accidentally end up back in the last dream where you left off.

There is a discussion of what to do about DJing and dream recall with DEILD here.