Clutch Fluid

[crsgmc]

I have looked around a bit and have not found any answers. I have a 1996 GMC K1500 five speed manual transmission. The clutch fluid is really bad, like it is the original fluid when the truck was built. The transmission is a Getrag, probably the one the truck came with. It has an internal slave. My question is how do I drain / replace the fluid. Gravity bleed would probably work fine. There are two things sticking out of the slave with access holes in the transmission. Is one of those to drain the fluid, and if so which one? I just finished replacing the engine, clutch, and flywheel and I should have done it then. I didn't know it was this bad until the engine was in. If I had to do it again I would have also replaced the internal slave as well. Thanks for any assistance you can provide.