So I was able to unsolder all three motor wires after a lot of choice words and hours of attempting to melt the factory solder. Once removed, the wires are soldered to small, slightly raised circular pads on the lower circuit board. They solder on quite easily, and the results have me happy it is not a one-and-done ESC.

Long story short - it can be done. Just have some strong drinks ready when the going gets tough.

judging from the OEM soldering, they are probably using a SAC305 or similiar solder for the initial job.

If true that requires more heat than the typical Sn/Pb rosin core solder to unsolder. Any of the eddie current based soldeirng stations will make quick work of that though (ie Metcal and clones). Also any of the soldering stations that have the heating element on the tip (JBC Tools, PACE, some of the higher end Wellers) will work great for that.

Helped my friend solder up the new Nitrde G2 this past weekend and is pretty impressed with this esc. Its not as big as other ESC, compared to his old HW XR10 Pro G3, its only slightly longer, not as tall, and much narrower without the optional fan. It only looks bigger because of the square design.

The G2 now have user replaceable wires, but make sure you iron is at least 100W or so. The manual suggested a minimum of 60W, I used a Hakko FX888D iron which is 70W and tip temperature of 480c and still struggled with desoldering the stock wires. I literally have to hold the iron on the ESC for 2-3minutes before the solder fully melts and Im able to pull the wires off of the solder post. I managed to remove the stock positive and negative wires from the ESC, but sorta gave up with the phase wires, I got it hot enough so I could reposition the wires towards the motor instead of straight up and stopped at that. The heat dissipation is pretty impressive with this ESC, with all the heat Ive pumped into the ESC, it wasnt as hot as other normal ESC after a rewiring job. Everything powered on just fine, the LCD screen wasnt affected at all with all the heat and worked pretty well out the box according to my friend. Much more smoother, better brakes, and pretty intuitive menu once you get the hang of it.

You should add a lower temp solder that'll mix and make it easier to desolder.

I dont have low temp solder but used some silver solder I always used to start melting but still took a while for the new and old solder to mix. I should look into some low temp solder as you said and see if it helps making soldering these wires easier

It doesn't need to be special low temp solder, just lower than the OEM lead free. Standard 60/40 will be enough.

It is not recommended to mix lead free solder with 60/40. It can lead to inconsistent joints. Instead I would use some liquid flux to help with the heat transfer.

I only use lead free solder.

You mix it to desolder, then clean it off and put fresh solder.

You can get inconsistent joints mixing silver solder with regular lead free too. If you don't know the exact type of solder used, you should be cleaning off the old solder anyway.