POKE 72BF,00

This removes the command;

72BF

DEC (HL)

Which is used to decrease the player life counter held at 66F0.

POKE 7B67,C9

Just RETurn immediately from the alien subroutine.

7B67

RET

POKE 6CB8,00

6CB7	LD A,01
6CB9	LD (66A4),A