I have large hands, how do people with small hands/short fingers do it?
Just managed to break the top of one of these bottles. I thought I used the
right tecqniue but failed here. Sovetek, GT badged bottles , instead of
domed top, nominally flat with a bit of a central pip.
Come replacing I go in the sequence , along the line of 2,4,or 6 sockets,
that allows a full finger each side of the dragon's teeth grips to depress
while pushing in the bottle. Then I place with top of the valve in my palm
and push down on the ledge area of the top of the bakelite base, with finger
tips. Doing so , the palm of my hand is barely touching the top but enough
pressure on this pip to induce failure. As such a light force , I assume it
was likely to soon fail from vibration & temp cycling. Failed in the ring
around the flat area.

Next time I see flat tops (flat not compatible with vacuum) I will cover
with a temporary grommet, before replacing, any other experiences/tips?

Perhaps change technique to making a yoke to push down on the spring
retainers , using chest , forehead or chin or something, and then use four
fingers on the base to press into the socket. Or some sort of chassis clamp
to depress the clamps. Then two fingers, unless a weakened socket, is not
enough pressure to overcome the resistance