This is mainly about terrain exploits which have to be viewed but the Korrak revenge twinking can be summarized as

1. Get legacy gear with gem slots and set bonuses.
2. wod pre-legendary ring + exalted ashen verdict ring from ICC.
3. Legendary cape if you have it.
4. if you use azerite traits stack them ilvl doesn't matter
5. Use oils (eg wizard oil) and level 60 appropriate consumables (they are cheaper and just as effective as hi-level).

You can do a mountain of dps with the above.

› See More: Alterac Valley/Korrak's Revenge Exploit Guide