Originally Posted by 3800_cruiser
When I replaced my LIM recently I took the thermostat out and drilled a small hole through the thermostat like this
The hole doesn't have to be this big, just big enough for air to pass through when coolant pushes it out. If you make a hole too big you will have issues warming the car up.
By doing this it makes it a bit easier to bleed the air out of the cooling system. You should still squeeze the hoses a bit. But when you finish refilling the system, go for a drive. Let it cool off for a while then top off again and you should be good to go, just keep an eye on the coolant level for a few days.
I drilled a 5/32" hole in mine at the 12" o'clock position of the stat, if you get the OE stat you should not have to do that though, they should have a hole already in them, I bought a 195F Stant SuperStat, so I drilled it.
Attaching a pic of an old OE Stat with the hole in it.
+1 to Dans method of filling and bleeding!