David laid this down on his screen :
O.K. - should have looked more closely on line instead of accepting that
30W is normal and 45W is large.

Plenty of 100W soldering irons for not much money, but 120W gets a tad
expensive.

A true 100w should manage it, but don't expect one of those instant
trigger type 100w irons to cope. Like a gun, with a trigger and and a
copper loop type element.

Whether soldering might be enough, is a different story. I suspect
originally it will have been spot welded. You might be better looking
up how to try that, with a 12v car battery.