I did 2x HIM this season on a way to my IM.
What I did was simply 1 week tapering before and 1 week recovering after.
If you are following a plan, simply start on the tuesday before cutting 20% of the volume downto 50% on friday saturday
For recovery, the opposite
For intensity, never more than 75% of my max geart rate (basically zone 2 max).
Summary:
mon rest day or normal trainig day
tue -20% volume, 75% max intensity
wed -30% volume, 75% max intensity
thu -40% volume, 75% max intensity
fri rest day or -50% volume, 75% max intensity
sat 30mins each sport
sun RACE
mon rest day
tue -50% volume, 75% max intensity
wed -40% volume, 75% max intensity
thu -30% volume, 75% max intensity
fri 20% volume, 75% max intensity
from sat you get back to the normal plan
I hope this helps.