Need help identifying unmarked pins on custom Arduino Pro

I need to burn a new bootloader with my USBasp, but I can't find the pins needed for it, there are 6 pins with no name only AVR.

Those six pins are almost certainly intended for a standard AVRISP type programmer.

Use your multimeter on the continuity setting to determine exactly which are connected to power, ground, MISO, MOSI, etc. on the ATMega chip.

On the other hand, if you have a genuine AVRISP programmer, it won't damage anything if you plug the programmer in the wrong way around. It just won't work. Note: the AVRISP programmer does not power the target.