In my opinion it’s better to use hotair because You won’t touch ec5 body so You won’t left any solder left on sides – if You left then You will have trouble fitting conductor element into plastic case and need to use lot of force!!
- Strip wire
- Apply little bit of flux then add solder onto wire
- using hotair heat ec5 pin and fill solder into hole (about half of hole)
- fit wire while heating, wait couple of seconds then remove heat source
- cold down and apply heat shrink tube
- fit pin into plastic case using flat screwdriver
- BEFORE STRIPPING ANOTHER WIRE MAKE SURE FIRST ONE IS FITTED INSIDE PLASTIC (or insulated) TO PREVENT ACCIDENTAL SHORT!!
Here pictures of that operation: