D&D 5e Cloak of Displacement

How would I go about implementing the Cloak of Displacement on the 5e Character sheet?  Is there a way to specify how enemies get disadvantage on the attack roll?  I suppose the player will need to remember to unequip it if they take damage?

I don't think there is an automatic way, unless you have highly automated your own combat. It would probably be best handled with a reminder. "Hey I have my cloak of displacement on" "OK, I'll roll with disadvantage". One thing I would recommend is to try the "Always Roll advantage" option on the sheet. If there is no adv/disadv, just take the lefthand number as the one rolled. If there is adv/disadv, take the higher or lower result as written. It makes combat much faster. If you want to  forestall abuse, you might consider instituting a rule that if the question of adv/disadv comes up after  the roll, the player/gm cannot simply take the more favorable roll. It must be rolled again.

You can mark the token with a token marker to remind you that the cloak is on, however that will likely require a lot of turning a marker off and on.

Hm...  ok, manual it is.  I guess you have to remember it when you're playing on a real table, so it's no extra burden on a virtual one.  Thanks!