Mate, I know exactly how you feel. I only got into RC at the start of the year and found myself wanting to swap a connector. Like you say, the YouTube folk make it look so easy but I made a right pig's ear of it. Ultimately, what made life loads easier for me was:
1. Wedge-shaped soldering tip instead of a pointy one
2. Proper lead solder (melts at a lower heat)
3. Flux (makes the solder behave)
4. Swapping the EC5 connectors for IC5s (they're loads easier to work with, tho much pricier)
I'm far from an expert, but the changes above have been a big help and I'm getting there.