Thank you so much for this how-to!!!
Usb port of my 26 months old N900 was still fine (I filed down usb plug's hooks since day one and always plugged and unplugged very gently), but as the warranty expired I wanted to try this strengthening technique to stop worrying about this issue. It was quite easy, thanks to these step-by-step guides! That's really a great community.

I'm from Italy, and if someone living near La Spezia needs help with this soldering, I will be glad to help.

My N900 also had the vibration issue (motor not rotating), which I was able to fix too, but I will write about that on the specific thread

Thanks again!