Mega2560 - Howto "RESET-EN"

Hi i need to disable auto-reset when i connect with serial connection,
First i tried with a 120 ohm resistor between 5V and "RESET"
and that didnt work.

Now i wonder how i should cut the trace, what should i use to do it?
does any one have a picture where it´s done?

And after i have disable the auto reset, how should i do when i need to upload a new sketch?

Here is a picture on my board.

The little pad labeled RESET-EN, next to the IOREF header pin and the large round capacitar, has a little trace between two solder pads.
You need to cut that trace. You can slice it right next to each solded pad and then push it off the board with a small soldering iron tip.
To load a sketch via serial you can press the reset button when the IDE shows "compiled xxx of 128xxx bytes". Might take a few tries to get the timing right. Or wire in a little switch to the 2 pads that you can close and then re-open. Or just 2 wires that can connect with a jumper.

Going to try that with a scalpel.

Ok, go slow & steady, don't cut something else by accident.