Yep, slowly heat it with the torch. make sure you have the flame about 1"-3" 'under / away' from the parts. this gives maximum heat to the parts. the thicker rod may require extra 'heat up time' so be patient. You'll know when it's hot enough, as you'll see teh solder just wick right in. You'll probably have to 'touch' it with the flame, to ensure you're still at tempurature. it all happens pretty quickly.

Soldering Irons I find take time to heat up the parts, and only heat a small area. hence why I prefer a torch, as you can move it around teh parts...

Also, let the parts cool natually. don't speed up the process, otherwise you'll get a 'cold solder joint' and that can lead to failure. At least it does in the electronics world...