need help to mod a cd player.

i am have 2 cd players.i like to mod one of them.could any one give me some suggest where to start.thank you very much in advance,you help is trully appreciated.
the units are: sony xa 9000 es and esoteric x 30.
Sorry about the delay in my response! I was not sure what x30 Esoteric is? I am familiar with the xa900es which is out of the question.

Contact Richard Kern and check out his web site I highly, highly recommend his work!
TRL is known for high value mods at a reasonable cost - $550 per unit. They work on lots of different CDPs including Sony. Email or call Paul Weitzel and he will tell you if what you have is worth modifiying and if so, what improvements you can expect. I have used TRL for all my digital mods and their work, turnaround time, communication, and service is excellent.