Ok I'll be a little more detailed than just post links. Many mods that relate to swtiches require desoldering, do the mod, then resolder the switch back. Mods like changing switch types, springs, stems, lubrication, or stickers all require this desoldering/resoldering process unless it's a PCB mounted switch. For desoldering, you'll need either:
1) soldering iron + wick braid: cheapest option since you'll already need a soldering iron, and wick is only ~$5-$10 depending on how much you get. I have some I I've found these take a long time and a pain the arse to work with. Sometimes it doesn't get all the solder that are deep in the hole.
2) soldering iron + manual solder sucker: this could be a cheap or expensive option, depending on which one you get. The cheaper pumps that are under $10 might not have enough suction force to get all of the solder out, and build quality might be a problem. The good one I linked works well, but is not as cheap.
3) radioshack desoldering iron: I found this to be a good compromise between ease to work with and price since it integrates a manual pump with a metal tip head to heat the solder. Suction is not as great though and sometimes leaves solder in the holes that you'll have to do again. For me, my tip only lasts 2-3 keyboard of desoldering and it needs to be replaced. Tip replacement is only $2 though. DON'T USE TO SOLDER since the tip is not fine enough for the job.
4) dedicated desoldering gun: expensive, ranges from $100-$200. They work really well, but the fact that you're asking about soldering equipment means you don't solder enough to invest in something like this.
For soldering, you'll want to get something with a base station because you can control the heat/temp. A radioshack iron outputs a constant 45w, which is too hot after it fully warms up. The tip also wears out really fast (although can be replaced). If you think you'll be soldering much more in the future, then look into all-in-one reflow stations if you're willing to spend $150+. Otherwise a Weller WLC100 for $$45 is good for keyboard related jobs.
