Good job, and now you now how to do it next time. I had to replace the entire valve on my old trailer as the screws had rusted out and a couple of the "ears" where the screws go in the corners had broken off, so a complete new valve was needed and the gasket repair kit was not an option. Problem was, there was no way to get the valve off without breaking the connection into the gray tank, something I did not want to do. Someone on this forum gave me the idea to use one of those rubber couplers with clamps shown in the link below. I simply cut the pipe off with my sawzall and installed the new valve with the coupler. Made the job fairly easy. Picked the coupler up at Lowes:
RUBBER COUPLER