Input shaft? leak

This is on an '89 AW4/242 4.0 w/210k miles. Alright, this may be a super noob question but it's driving me nuts. Yes, I did a search. Two weeks ago, I pulled my driveshaft to put new u-joints in. After installing it, and driving it home I noticed a leak coming out of the transfer case. I drove it for about an hour last weekend, and when I parked it the fluid just oozed out. Changed the atf, and that made no difference. So what's really going on here, and how bad is my wallet going to hurt?

You probably damaged the Tcase output shaft seal while re-installing the slip yoke. That seal is pretty easy to change I believe. Next time make sure the slip yoke is clean (clean it off with Brakleen or Carb Cleaner, then wipe it dry with a rag), and go EASY while sliding it in. Yep...that's what she said

How tough is that seal to replace? Tell me I don't need to drop the t-case....

You don't. Just pop the old seal out, pop a new one in. You'll understand when you see the new seal, it's really easy.