D&D = NCGR
Strength = Strength
Dexterity = Agility
Constitution = Health
Intelligence = Intelligence
Wisdom = Awareness (closest fit)
Charisma = Social
?(put a 10) = Luck
?(put a 10) = Spirit
HP = Luck Points (This just makes it explicit that you are avoiding the hit rather than soaking it)
Negative HP (ie till you die) = Body Points, Physical damage. Close enough.
For ease of writing these are switched order
NCGR = D&D
Attack Modifier = Whatever bonus you get "to hit", ThAC0 is 18? thats 2 above starting so +2
Defense Modifier = Any bonus to AC for shields, high agility, and whatever your attack bonus is.
Damage Reduction = Do you separate out Armour bonus from shield or agility bonus? Its that.
Presence = Are you a bard? Its what your attack bonus would be as a fighter. Not a bard? Its 1/3rd your level. Add your Charisma bonus (if that exists in your system).
Stealth Modifier = Couple of options. If you are not a thief, its 1/3rd your level. Are you "Thief Like", ie a bard or ranger or something? 2/3rd your level. Are you a thief? Either its your level, or take the average bonus for thief skills (if its a %, then +1 per 5%) and that is your stealth mod. Add your wisdom bonus if your system has one.
NCGR has alternate spell systems so just use yours.
If you don't have anything to cram in "?" consider them 10.
Specific things to Neoclassical Geek Revival:
Fate Points: These can be cashed in to re-roll a die, or regain some Luck Points (ie HP). Think of them like Benny's. You get them by being awesome.
Saving Throws: You have to declare you are doing something to get a saving throw. Could be as simple as "I Look away", or "I jump out of the way". If your system has more formalized saves just pick one that is most appropriate.
Lucky Number: Pick one between 1 and 20. If you roll it on a d20 announce it.