I have read several threads regarding the joys and tribulations of whistle head removal for tuning / tweaking.
The popular method seems to be to immerse the head into hot (but not boiling) water for several seconds, protect your hands and give a twist.
I also read that damage can be done to the plastic heads in the process.
Taking all this under advisment i removed several of the heads of my now growing whistle collection, and i found the following method worked very well and absolutely no damage to the head is likely.
Step 1. boil the jug
step 2 have a cuppa
step 3 refill the jug to completely full, fingers crossed you possess one
of the new tall jugs
step 4 immerse the BORE of the whistle into the boiling water to a point
just below the head…no need to immerse the head at all.
Only a few seconds (10 - 15)are necessary, the heat of the bore will radiate up to the head and work on the glue much quicker and will be much less likely to damage the head / fipple.
Be warned use a tea towel to grip the whistle after immersion, its gunna be hot, give the shaft a quick twist. hey presto.
I hope this is a help,
Regards David
Interesting. There is the alternative “heat the shaft (but not head) with a candle or lighter” approach, which resembles your shaf-tsubmersion technique.
What whistles did you try this on? Specifically have you removed the head of a Generation C? I’ll be greatful to anyone who can tell me a reliable and easy way to this. Heck, easy works for me, forget reliable.
Thanks for sharing.
The whistles i referred to are my generation d whistles, but i see no reason why it wouldnt work on your c whistle bloom,
I used to loosen the glue on my arrowheads, stuck with epoxy, using this method, i used to have to leave the shaft in the water a bit longer but worked well.
Good luck
Well, I have tried it on Generation Cs and it was a big pain each time. Very hard. And I’ve cracked some heads in the process (really I shouldn’t take my tweaking frustration out on my roommates, but what can you do). I also find that after removing a Generation C head (admittedly by submersing the head), it becomes necessary to sand down the shaft to get the head back on. Very very annoying and frustrtating.
Isn`t that weird about the C Gen. I had the same battle royal with my C. I think though that the dents just below the head kinda give it a certain charicter(is that how you spell that?) They probably act as perterbances too. I know this though, that C is an outstanding sounding whistle with no faults. One of the best tweeken jobs I ever did. 
Tom
I think it is important to clarify,
If at first you dont succeed ( and nothing succeeds like a parrot with no beak), try try again.
glue will soften at different temperatures,
whistle bores will heat at different temperatures,
the point i want to make is that first the bore will heat, the glue will be first to soften before the plastic of the head will.
referring to experience of my mis-spent youth, a twist top bottle cap will come off much easier with a short sharp twist. the same applies to head removal…but if it doesnt come off easy , repeat the process until it does.
Immerse the bore the full depth of the whistle to a point just below the head, and heat until the process is easily performed.
c whistles are slightly longer then the d, you may need a different container to take on extra water.
good luck
oh and bloomfield, what a good excuse to go out and buy a new c whistle just to try the theroy out…WHOH 
regards David