The bleeder is notorious for leaking. From the dealer, it comes as the entire hose, which connects at the t-stat housing, and under the manifold. Manifold itself doesn't need to be removed, just throttle body, and piece behind the throttle body.
Most people just replace the bleeder, or even install a brass fitting into the hose in place of the bleeder.
Take your engine cover off, you'll see it right away, front and center above the throttle body. Only thing to be concerned with if just replacing the fitting, is that they tend to break apart inside the hose, and you need to be careful to not allow any plastic to remain in there.
One of the first things that went wrong with my LR3 when I purchased it was this bleeder failing. I didn't want to have to get the truck towed in to the dealership (it was under warranty and I was getting a bunch of other stuff fixed as well... otherwise I would have just ordered the part and done it myself), so I replaced it with a brass straight through fitting from the auto store. It took me at least half an hour (if not longer) to bleed the system and I had my IID tool hooked up, monitoring the oil and coolant temp the entire time. It was a royal pain in the ass. I would not recommend this, but it can certainly be done.
Nowhere in my AllData DIY guide did it speak about this bleeder in their coolant replacement procedure. The air venting procedure described was very similar to the one for C5 Corvettes (I've owned two and the procedure worked on them. Worked for my LR3 and then I had the leak).
I found this post while trying to figure out my coolant leak, evident on the back of the block and dripping down the transmission housing. I feared it was under the intake; maybe the bleeder hose where it connects. While cleaning the area yesterday, in hopes that a loose bleeder cap was the reason for the leak (it was barely finger tight) and cleaning the area to make it easier to spot the leak, the entire tee broke off into my hand (more fragile than the force needed for cracking an egg). Seeing as how the bleeder isn't mentioned in the air bleeding procedure I merely replaced it with a 3/8" fuel line splice (metal) and hope that will take care of the issue, now and in the future. Seemed ridiculous to replace the faulty plastic tee with another plastic tee, even though this one lasted nearly 100K miles. Have my fingers crossed that this was the origination of the leak and that a simple $5 piece has fixed it.
The following is the coolant refill procedure. I hope somebody finds it useful.
Loosen the coolant expansion tank bleed screw.
Fill the cooling system, keeping coolant to the upper level mark of the expansion tank.
Tighten the bleed screw.
Install the coolant expansion tank cap.
Start and run the engine at idle until the normal operating temperature is reached.
WARNING: Release the cooling system pressure by slowly turning the coolant expansion tank cap a quarter of a turn. Cover the expansion tank cap with a thick cloth to prevent the possibility of scalding. Failure to follow this instruction may result in personal injury.
NOTE: When the coolant bleed is complete and prior to installing the expansion tank cap, top-up the expansion tank to 30mm above the maximum level.
Switch the engine off.
Remove the coolant expansion cap, allow the level to settle and top-up so that the level is 30mm above the upper level.
Allow the engine to cool.