IMO as ARU is a forced conversion into K then K shs will show up in Accts maybe late Monday but surely the Dealers will have the job completed by Friday.
In the interim if you want to Sell, check with your Broker as IMO K can be sold on a "Delayed Delivery" basis or as a Covered Short.
As said ... check with your Broker as these are the Common Sense selling avenues I see - I've been so wrong with this investment that I'll no longer rely on Common Sense.