It Helps if you work in an industry that uses all the rework tools to do component level replacement on circuit boards. But typically the very large parts on this particular board would require a lot of heat to flow the solder to remove the relays. You can buy basic soldering irons to do small stuff but they are in no way capable of delivering the heat needed to do this kind of thing. The alternative would be a small torch to heat the metal, but I wouldn't do that unless you are very confident in your ability.