Unlimited lives:
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 5472,99
POKE 5686,128
POKE 5677,128
POKE 7623,165 

Unlimited lives (alternate):
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 5472,99 

Unlimited lives (alternate):
Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 5472,9
POKE 19722,99