You should be ok with a good 30-40 watt soldering iron. I use rosin core solder(which has the flux "built" in), I also use the same stuff for electronics. Don't use silver solder or acid core, as they'll "eat" any parts close by after a while. As with any soldering job, be sure to clean the joint before AND after with alcohol(isopropyl or denatured - not whiskey) to remove any flux, debris, and residue as they are very corrosive and will create problems later on, and will also weaken the solder joint. You should end up with a solder joint that is so shiny that it looks like chrome.