On Aug 2, 2011, at 12:06 AM, Gilles H Turmel wrote:

> Hi,
> I�ll rephrase my request:
> I do I remove the knob on an adjustable armrest? Once the knob is removed how can I get the inner mechanism out to be welded?
> Best regards.
> Gilles Turmel

Do you KNOW that the mechanism NEEDS welding? Or are you presuming that because the arm is "floppy?"

To remove the arm, forget the adjuster knob .... stick your fingers into the space between the arm and the side
of the seat back and pull the arm cushion material away from the seat so you can see the steel pivot point.
There is a roll pin that can be driven/punched out of that joint in one direction. Determine which end of the pin
is smaller than the other, and use a flat ended punch (a properly prepared large nail will work) to drive the roll
pin out of the joint. Move the arm up and down while pulling it outward and it will come off. 

It is likely that the small allen screws have come out/loose and no longer hold the steel pivot to the seat back.
If that's so, use some lock tite on the ends of them and put them back in and reverse the above procedure
to put the arm back on.

I happened to have an upholstery mallet, small hammer, which made tapping the roll pin out and back in
a little easier.

bob