ATmega2560 bootloader to use more i/o pins

Dear CrossRoad
Thank you
But I am confused
Waht did you mean by saying sketch from the bootloader
If I understood..
I should write a sketch and when I want to load it to the board I would press the Tools>BurnBootloader ?
Would it make the Hex file ? (let me remind you that I am burnning using the studio which uses the Hex files)

As for th DTR- ok I dont really know what is a DTR (I feel stupid) but I am a very good HW but not SW guy :blush:)

If I understood...
After loading the Bootloader (assuming that it worked for me), I need to get an FTDI module (Do have any link that i can see what it is?)
How should I connect it to my board ?

If I would use the UNO(or Due which I have) I I connect the reset to the GND it wont work !
What do you mean by Start downloading in the IDE please explain what does it mean

Thank you for your time
I appritiate that very much