If the account was closed as 'current/in good standing' but with a few late payment notations in the history, then just those late payment notations will be removed come March 2020 -- the account will remain with a clean history until it is removed in its entirety (accounts closed in good standing remain on reports for up to 10 years after the closing date).
If the account was closed and not current/charge-off status, then the entire account will be removed when it reaches its 7 year mark.
There is no action for you to take -- just wait it out, it'll fall off automatically and your score will adjust accordingly.
And just to add a little info to how this works -- late payment notation removals vary by bureau. Experian will remove the entire string of lates (for ex., if you have a string of 30, 60, 90 day lates, all will be removed at the same time in March 2020); Equifax and Transunion will remove each notation indivdually, as it reaches its 7 year mark (so 30-day will drop off in March, 60 day in April, 90 day in May).
Also, Experian apparently deletes these notations 2 months early; Equifax deletes 3 months early, and Transunion deletes 1 month early -- so they will not drop from each report at the same time. Below link is a thread on this topic to give you an idea of how it may go... this thread had been started and updated by a poster as their reports were undergoing this process: