arduino nano com port change

hey guys

I seriously need with my arduino nano i cant get a ken sherrif code to upload onto my arduino nano

THIS IS WHAT IT SAYS

Using Port : COM4

Using Programmer : arduino

Overriding Baud Rate : 115200

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x4c

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x4c

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x4c

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x4

I watched a youtube video they said to use COM 3 but i dont kow how to do that.

THAnks

Select Tools > Processor > ATmega328P (Old Bootloader) and then try uploading again.