Proper technique for removing crown from stem?

[Giannifive]

I'm assembling my first watch from components, and I have what is probably a basic question: What is the proper technique for removing the crown from the stem?  I'm trying to get the service crown off the stem of a new movement.  I'm using a pin vise to hold the stem, but it just spins as I try to unscrew the crown.  I'm not clamping with a lot of force, out of fear of destroying the stem.   Is there some trick to this?

[jdm]

The crown of the service stem is not really supposed to be removed, as it's made of grippy plastic and could be even glued.

Another stem should be provided with the mov.t, or bought separately. 

If you want to reuse the service stem see if you can just cut it to length, otherwise heat the stem a little and grab it with ridged pliers near to the crwon.

[anilv]

Just pull as you unscrew.. should come right out.

[oldhippy]

Hold the stem with your pin vise where the arrow is pointing and tighten right up. Then unscrew the button. New movements come with the plastic buttons so they can be tested winding up the normal way before they are sent out to the customer. There is no reason why you cannot use the stem. It is a waste of money buying another. 

[vinn3]

7 hours ago, jdm said:

The crown of the service stem is not really supposed to be removed, as it's made of grippy plastic and could be even glued.

Another stem should be provided with the mov.t, or bought separately. 

If you want to reuse the service stem see if you can just cut it to length, otherwise heat the stem a little and grab it with ridged pliers near to the crwon.

    yes,  "ridged pliers" for stem flats.  the parallel   jaws of the pliers grip the flats of the stem,  or a pinvise for round area of the stem.  best to buy a new stem.  vin

[rodabod]

What Oldhippy suggested is the traditional method. Hold the pin vise in a bench vice if you need to tighten it more. You can grip the flats of the stem, but it’s a weak point, so that can potentially snap there. 

[Giannifive]

19 hours ago, oldhippy said:

Hold the stem with your pin vise where the arrow is pointing and tighten right up. Then unscrew the button. New movements come with the plastic buttons so they can be tested winding up the normal way before they are sent out to the customer. There is no reason why you cannot use the stem. It is a waste of money buying another. 

Thanks for the detailed response!  Once I realized where exactly to clamp and that I should "tighten right up" I was able to get the service crown off easily.

[oldhippy]

That is probably the strongest part of the stem. Far better and safer then holding it by the square, at that point they can break.