I've played H?rnmaster in H?rnworld for 10 years, so probably can help you.
I've just read the Epic rules so I may have missed a thing or to but I see no difficulties in adapting Epic to H?rnworld (In fact I thought about it while reading).
I don't know how familiar you are with H?rnworld but it's a good thing to get H?rnmaster rules too (the Gold edition
is the best to me) You will find many useful stuff in those. It's main inspiration is 11th-12th century England. Muddy, cold and rainy. It's a strongly feudal society (I'seen that you were looking for Medieval society informations in another post, H?rnworld is a good start). The main differences between EPIC and H?rn revolve around magic. H?rn is a low magic setting and magic is mainly elemental.
Overall I would say that H?rn is less epic than Epic RPG, I would put Shen aside as most of the arcane ubber effects. Magic is descreet and frown uppon in H?rn. I would keep Theurgy for none pvarik practitioneer and Mentalism for Psionic gifted ones.
Here are my first thought for an adaptation :
? Races : Human, Sindarin, Khuzdul (dwarves), Gargun (orcs and goblins). Should be rolled 1-89% are humans
? Stats by rolling as usual
? Backgrounds and parent occupations are ok in Epic, but stik to H?rn mood I Would tweak the tables. Most people are peasants, you have to be very lucky to be of an upper cast
? Professions : designing new ones acording to H?rn setting should not be difficult. Theology and religious order secrets should be reworked a bit to stik to H?rn religions, especially Morgath and is terrible gift.
I think it will be the main stuff to work at. Pvarism (H?rn magic) is an Art by Himself. I would divide the Pvaric wheel in specialities. But On H?rn, you're attuned to an element of the wheel and a sun sign. Those Have a big influence on the Pvaric concepts you can manipulate.
Once attuned, you may have bonus in your concept and malus in the opposed concept, both for learning and practicing.
If you're not familiar with Pvarism I may give you a hand.
That's it. Easy no ?
Beside that, using H?rnmaster materials should proof easy, stats range from 3-18, skills are percentiles (drop the unit, you've got the Skill Level),
Armor is a really nice part of H?rnamster rules (many hit locations, materials and layers), plate is rare and not articulated.
Many tables for charcter generations can be useful to craft an Epic H?rn character and professions
Don't hesitate if I may help.