I can solder pl259s, but I don't know how to tell you I do it.  I clamp
the connector in a small vice if I can with the center pin pointing
upward.  I use a weller gun that heats and cools rapidly.  I think it is
72 00 or 8200, not sure of the model any more, but it is dual heat.  I
place the gun and solder where desired and pull the trigger.  Keep just
enoughtention on the solder so you can feel it when it melts and starts to
flow.  Good luck.
73s
Butch Bussen
wa0vjr