[Arakon]

at the very minimum, he should have a 0.4 mm tip on the iron.. anything bigger is VERY likely to fuck things up. 0.4 or smaller will do fine, and I recommend using enamelled copper wire. it's easy to solder and alot less likely to cause bridges and shorts. 0.2 mm is recommended, 0.1 mm is easier to solder, tho.