Change the terms and phrasing, certainly. Shift some numbers around, of course. Don't use anything like the same kind of presentation, ever. Use the OGL properly, for example by putting the relevant stuff into section 15.
And you're probably good to go. Just don't overdo it. If you're thinking of selling this thing, it might be a little bit more risky. Not to mention pointless.
But if it's free - which is what you had in mind, right? - I can't see any real issues, provided you follow at least the spirit of the advice I've given here (i.e., don't be daft.)