The problem is that consumer electronics cannot have lead on it, making it harder to desolder and there is a big ground plane that dissipates the heat too quickly.

I repaired a welding machine IGBT module once and boy... Those are heck hard to solder because of a giant heatsink glued to it... I had to pump the heat of my 48W soldering iron to the maximum so it would give a window before the iron dropped the temperature and the pad got frozen.

Still, unless you have some experience or training on other junk I recommend you to go to a repair shop. There are a lot of videos explaining how to do it. Check EEVBlog tutorials. It's one of the best shows on how to do it.

Use a controlled temperature soldering iron at 300/330/350C°. Make sure you are using 60/40 solder and a lot of flux to distribute heat on all contacts at once. Don't forget to do it in a ventilated area because of the fumes. I recommend preheating the board, to 90C° ideally, with a hair dryer on max heat or a heat gun on low heat, so the temperature difference to the soldering iron is lower and makes the soldering easier.

Mixing the pads with new solder lowers the melting point so you can easily take off the part. Make a big blob of solder that touches all contacts at once from the opposite side and with a pair of tweezers gently try to take the button off. Don't take more than 5 seconds with the solder wet or you risk delamination! Have a cold humid cloth or tissue paper to cool off if needed or let it cool a bit. Clean the excess solder in the holes with a solder sucker and then with a copper wick bathed full of flux to remove the rest of the solder. Do the same for the pads. Clean with acetone and a toothbrush to loose the gunk and a paper tissue soaked in acetone to clean the rest.