You can do it yourself, but it likely to be a lesson in frustration. However, with gaps the size of the ones you are talking about - it may be worth it. I wonder, is it possible that it is the wrong hood? Is it a smoothie? I cannot imagine stock parts being THAT far off.
That being said, the hood is non-adjustable. 4 bolts hold it on. Probably a good thing - as it is too large to manuever around for adjustment. You can, however, adjust the front fascia quite a bit, as well as the headlights.
The factory does seem to use quite a few shims...
The front fascia can come off in one of 2 ways - the easy way involves just "peeling" off the skin, and leaving the front bumper bolted to the frame horns. I am not sure how much flexibility this gives you forward and back, though, but it is how they do it at the factory. The fascia is VERY flexible, so you should be able to get some decent adjustment. MAYBE you can get more front / back adjustment by removing the entire front bumper assembly, but that is a royal ***** to get off - especially 2 bolts to the inside of the headlights that must be accessed by going in through the small and painful opening between the hood and fascia. The headlights have quite a bit of adjustment - three screws can help you with forward, back, twist and up / down.
Be forewarded, adjusting one of any of these will invariably mess up something that you thought you had right already.... Kinda like the ld Rubik's cube- sometimes you need to go backward to go forward.... Good luck!