there is a lead free solder available for domestic water lines that should
work just fine for repairing the leaks on your extractor any local hardware
store should be able to help.  The  area that has the leak must  be cleaned
and fluxed , use a soldering iron or a small hand torch its kind of tricky but
bee  patient and you should be able to solder it yourslf  the solder should
flow onto the suspect area  it doesnt matter how the solder joint looks as
long as it doesnt leak . good luck