I haven't really played much with this for a while but it shouldn't be too tricky since the basic stats are similar and the stat-scale is similar.
I'll have to look around to see if I have any notes on this.
Marv / Finarvyn DCC playtester (2011) S&W WhiteBox author (2009) C&C playtester (2003) Builder of the TrollBridge for T&T; Amber Diceless player since 1993 OD&D Player since 1975; Metamorphosis Alpha since 1976
"Don't ask me what you need to hit. Just roll the die and I will let you know!" - Dave Arneson
I have, as you will see in the next issue of Fight On!, converted RQ religions to D&D. With a bit of jiggery pokery (technical term there) it worked well anough for Humakt, and in my notes I have Chalana Arroy and Issaries done with little problem. Then Calithena asked me to do Thanatar and things have got a bit complicated, I have half a dozen pages of guff and I am not even half done.
My advice on converting RQ to ODD is, generally, don't. Glorantha has a feel all of its own that does not IMO translate well to D&D, and Runequest is a fine game with its own merits, so play the material as originally intended. I only stole the religions from RQ becuase I felt so disapointed with Deities and Demi-Gods and the weedily biblical flavour of Clerical magic in D&D.
Bits I would steal for a D&D game (and have done):
Equal Rites for Trolls. I liked the idea that monsters in RQ are people too and endeavoured to give my Orcs and other humanoids individuality and culture, rather than just being a bunch of mooks for the PCs to mercilessly mow down to feel 'heroic'.
Dirt and primitivity. D&D's 'medieval' world always felt like California without the firearms and cars to me, there was none of the feel of an alien culture with no plumbing, mere lip service to feudalism as actually practised and so on. Glorantha's bronze ageyness appealed to me, heroes living in mud huts and defending clans of stickpickers against evil decadent mad-heads who wore actual shoes! Needless to say Griffin Mountain is my favourite campaign book ever.
Baboons. Loved 'em, I was a baboon for many adventures, I knew the names of all my fleas, my great-great grandma's spirit looked after me, and nagged me, and when I bound her spirit into a vulture I thought she'd be pleased...
But I guess your question is more technical. My suggestions are that the stats are straightforward enough - dump POW totally - gague class by looking at the best skills, guess at level by taking top skill then dividing by 10 for fighter and theiving types, taking number of runespells divided by 2 for magic types. Ignore battle magic - all part of that pizzaz that makes an 8th level PC fighter have the same HP as a giant.
D&D is great for the Heroes and Superheroes and monsters like the Crimson Bat, and for big combats -- the level of play after completing one's Quest for a Rune, the level of the Hero Wars rocking Dragon Pass.
Prax and (especially) Balazar are relative backwaters. D&D magic is simultaneously too rare and too powerful, the way the class system works. I would miss the 'gritty' RQ combat except for Blackmoor rules, and the skill experience and training systems could be adapted, but the cults and magic system and especially spirits are really distinctive.