Rebel,
Personally I prefer and Iron over a gun any day, the guns are too cumbersome and the tips are usually too large. In my shop we have 2 slodering stations similar to these http://www.radioshack.com/product/in...ductId=3348441
And in my truck I carry one of these http://www.radioshack.com/product/in...ductId=3348443
Both are very expensive to just use once in a while, but I use them almost daily some weeks. One of the cheaper units @ RS would do just fine, I would suggest looking for one with a smaller pencil tip on it. Also, I prefer to remove all existing solder from the contact pad or ring that I am trying to solder to. They have manual suction solder suckers or copper mesh that will soak up the hot solder off your contact. I will also flow out the solder on the wire and "flick" the wire to have the hot solder fly off(WEAR SAFTEY GLASSES!!!!!!) Watch the hot solder it burns(insert experiences). If the wire looks crappy try to clean it up or snip the wire back some and start with a fresh end, if the wire has a blackness to it(not copper or silver) that will give you nothing but troubles when you try to tin the wire. You can rid the blackness with a scotch brite pad to return it to a "clean" wire. The blackness usually comes from water intrusion under the insulation around the wire. With the wire ready for tinning, start to heat the wire for a few seconds and then start to flow the sloder into it so you coat the stripped end. Do not use plumbers solder it's much to large for wiring work, pick up a smaller solder
http://www.radioshack.com/product/in...ductId=3348443 The smaller solder will flow in better it takes less heat to get it to flow, the larger solder acts like a heat sink and you'll end up melting the insulation off the wire before the solder flows and once it does you'll probably end up with a cold solder joint which will fail when you least expect it. Here is the solder remover http://www.radioshack.com/product/in...ductId=2062744.
Cleanliness is next to Godliness!!!!!!!! On the switch side remove all solder and clean it up good the place a small blob on the contact, then with the wire ready, heat the switch side for a short second or so them move the wire close, transfer the iron to the wire and get that solder to flow, once flowed move the wire and iron to the switch and that solder should flow quickly, remover soldering iron and hold wire steady, andy movements can cause a cold solder joint. I'm sure you probably didn't need the tutorial but I don't like to see people struggle, I instruct all our guys that come thru our shop that soldering takes practice--lots of it. I wish I could solder like I can now, but 20 years a go when I was into RC cars.
Good luck with it Grasshopper!
1985 Honda 125M (My first Trike--Still have it)
1986 Honda 250SX
1981 Honda 110
1982 Honda 110
1986 Yamaha YFM80 (Sons quad)
Past rides: 1983, 1984 200X, 3--1985 Kawasaki T-3
1987 CR-80, 70's vintage XR75, RM 370