Confirm fuse settings CKSEL=1110 SUT=10 (other fuses are left at default)
Run Bascom programmer and set chip to ATMega8
Erase chip
Load AVR-Doper hex file into buffer
Program and verify ATMega8
Insert chip back in programmer
Test chip on blank AVR
Note: I now keep a spare ATMega8 chip on hand. This allows me to use the USB programmer to upgrade itself. I load the new hex file into the spare chip and then swap it with the one in the programmer