With AVR Programmer

Some AVR programmers you can use:

• SenMod on Amazon ~$10
• Sparkfun Pocket AVR Programmer ~$15
• Sparkfun Tiny AVR Programmer (no wiring needed!) ~$20

Connect 6 pins on the AVR header to matching pins on ATtiny.

Either using a breadboard, or on the Sparkfun Tiny AVR Programmer just by putting the ATtiny in the dip socket.

Add ATtiny support to the Arduino IDE

Follow this section from the tutorial on using the Arduino UNO as ISP.

Configure Arduino IDE for the correct chip.

First Burn Bootloader, then choose Sketch > Upload Using Programmer to upload your program to the ATtiny.