I have a pvc, 4/4/2, "Y", with an adapter glued into the 2 side. The adapter allows for a threaded 1/2" pipe. I would like to some how, change the 1/2" opening in the adapter, to allow a 3/4" pipe to enter. The 3/4" line is for the a/c drain. I can not remove the "Y". I would like the opening in the adapter to be 3/4". I do not want to run 3/4" pipe to the 1/2" opening. Is there a way to modify this glued in adapter to get a 3/4" opening for 3/4" pipe?