There are two generators on the ground in front of Dr. Octopus. Use the boxes
that slide by on the moving floor to destroy the generators. Web grappling then
throwing works very well. The main problem is preventing the generators from  
shooting the boxes you intend throw. The lasers will also take some of Spidey's
health but it shouldn't be a real issue. For the most part the lasers can be  
avoided with timely jumps. Even if they do connect they don't do a huge amount
of damage. The best method for destroying the generators is jump and bring a box
to your possession with webbing and throw it while in mid air. After connecting
with a couple boxes on the generators Doc Ock will jump to the ground between  
them with a thunderous green shockwave. Jump to avoid taking damage from the  
wave. While Dr. Octopus is fixing his generators move to his position and wail  
on him with the X button. He may use one of his arms to knock you back but just
get up and continue to punch. Eventually, the villain's health is depleted and
he decides to join the fight.