Originally Posted by locutus
If ya got a big enough pot, boil it.
I used this method when I changed out the Lyman lube in my Lyman Lubrisizer for Rooster Red a few years back. Remove the top cap along with the die and die nut. Suspend the unit so it will remain vertical in the boiling water. Use a coat hanger for this. Get a large pot of water boiling on the stove high enough to cover the entire unit, and just toss it in. After several minutes there won't be any lube left in it. Lay it on some old towels and blow it dry with compressed air while it's still hot. This will blow out any excess lube stuck in the nooks and crannies. Then spray it liberally with WD-40 to remove any trace water and blow it again. You should have a nice clean unit ready to receive any new lube you want to try without contamination.
Stay away from hair driers and heat guns because you can easily get some areas too hot and others not hot enough. The hot water will heat the entire unit uniformly, and you won't run the risk of melting any O-Rings or rubber seals. This method will also get any old, unwanted lube out of your dies. Just toss them in the water and give them the same treatment afterward.