You can tie a "metal connecting ring" to the end of the main line of the rod and the lead drop, and then take off the lead drop from the connecting ring after reeling in the rod. As the connecting ring is bigger than the tip of the rod's guide ring, the main line and the connecting ring will be fixed on the tip of the rod.
It is recommended to hang metal connecting rings on all other fishing sets, so that they can be changed quickly and easily according to different combinations.