[Elecraft] Variable Inductors Stuck

[Gary Thomas]

Hi. Im Building the xv222 which is supplied with three
can type variable inductors (L15, 16, 17). The cores
of the inductors are frozen near the top of the form.
Manaual instructs to exercise the inductors before
placement  using the tuning shaft. Manual says they
may be tight but they are frozen. any suggestion on
how to loosen the cores without damaging them? Thanks
Gary AA1UE