it's gorilla glue. read the directions, try not to make a mess, make things stick together incredibly effectively, like maybe epoxy level of effectiveness. note that the tip needs to be cut off, there's no weird trick to it, it just needs to be snipped off and then you can put the cap over it when you're done. additionally, when the directions say THIN LAYER, it's a thin layer, this stuff expands and you'll see some "great stuf" around the edges of your seal if you use too much.