We have created a super short video showing people how to keep the seal in the Big Dipper lid (see below). Here are the instructions in writing - Take your empty dipper lid, and put it upside down. Then place the dipper seal on top of the groove for the seal. Then take your empty dipper cup and place it upside down, on top of the lid, and squeeze. This should push the dipper seal into place on the lid. Flip the dipper right side up now, and remove the bottom cup. Now your seal should stay in place inside the lid.
Here is short video showing you how: