Voltage regulator brush replacement/soldering ?

[Dave C]

Could someone tell me what it takes to replace brushes on the voltage
regulator WRT the soldering?

I've heard others say silver solder is what is holding the brushes on and
that a high temp is needed for it.  But no one ever gave specifics.  What
temp does this stuff melt at?  And what kind of soldering station would
supply the needed heat?  I cranked my soldering station up to the max of
850 degrees with no effect.

Dave C.