Quoted from Dr_of_Style:get yourself a dremel tool and a brass wire wheel.
clean each part needing solder, as well as the wire ends.
if you do not clean them, you will be fightin oxidation, "solders enemy". and you will hate soldering.
That is total over-kill, a dremel to a solder pad? Odds are she will rip the tab right off. If the solder wont stick, just lightly scuff the pad up with some sandpaper.
However, when it comes to buying tools, nothing wrong with a bit over-kill. This is my favorite soldering iron and if you have Amazon you can get it at your front door in 24hrs. Technically all you need to focus on is a grounded iron (3-prong outlet) with a temperature regulator and a nice tip, as well a nice handle to hold onto so you have better control.
https://www.amazon.com/gp/product/B000BRC2XU/ref=oh_aui_search_detailpage
As for solder, the thinner the better in my opinion. It heats up faster and you have have less drips and more control over small areas.
