greg99,
i just installed an o-ring kit on my 2000. It takes a 1 1/8" deep socket with deep clearance (i believe it was 2 1/2") I used a black iron deep socket since they have more clearance. I show a pic or two of where it is and what is comprised. Try and plug the hole with a rag or something after you remove until you change o-rings and replace. the kit cost me $16 or so at Intl (1825806C92 IPR Seal Kit) but you should check to see if the same p/n kit applies to your 99.
hope this helps. see the pics...