Now we have to desolder the scroll wheel rotary encoder (Mouse roller wheel Encoder).

Put your pcb into pcb holder or use helping hands. If you don't have any of these, use something to lift it away from plastic or any material that can be melted or ignited.

You can use a soldering iron or heat gun to desolder the rotary encoder. My preferred method is using soldering iron, so that's what i did.

The rotary encoder is held in with 5 pins. You have to desolder all 5 pins, apply flux around all 5 pins and use desoldering braid with soldering iron to remove solder from pins. [IMAGE 1]

If you have problem with melting solder, add new fresh solder to make it easier to melt. If your soldering skills are not great, you can use pliers to cut off pins of the rotary encoder and remove each pin by itself. Make sure that you have removed solder from all holes otherwise the new rotary encoder will not fit in. [IMAGE 2]

My preferred soldering iron temperature is 360°C, but you can use whatever temperature works for you. If you are using a flux that has to be cleaned off, I recommend that you use isopropanol. Since I'm using no clean flux, I don't have to do that.