I went and commented out these lines but deleting them should have the same effect..
LDA $1570,x ; \ makes hammer bro jump
CLC ; |
ADC #$77 ; |
AND #$E7 ; |
BNE NO_JUMP ; |
With those not read the hammer bro doesn't seem to ever jump up or down, but I'm not sure if anything else should be commented/deleted. So this is a half-ass fix but i don't know sprites well enough to be anymore help.