desoldering an SMD resistor is actually pretty easy. Just blob some solder on your soldering iron so that the ball on the end of your iron is about the width of the resistor. Then basically place the iron right next to the resistor with slight pressure to the side. the blob of solder will transfer heat to both pads, and it should dislodge pretty quickly (~2s or so). If it doesn't budge, feed in a bit more solder right at the resistor.
It would certainly help to have a temperature controlled iron (but not required). If you are buying an iron new, there is no reason not to buy a temperature controlled one these days. Something like the SH72 is more than adequate for this (~$21 on amazon, cheaper on aliexpress). There are also much better ones available if you are willing to spend some more. (I highly recommend any of the T12 soldering stations ~$50-60 on aliexpress)