One of the igniters on our range (one of the four top burners) is cracked and needs to be replaced. I have already ordered and received it.
In my inital effort to remove the burner in order to replace the old igniter, one (1 of 3) of the sheet metal screws holding the burner in place sheared off

at the screwhead. At this point I stopped to ask your advice.
1.) What is the proper way to replace the igniter on this range?

From the top of the range? I do not see any other way? This was as I was trying to do when the screw broke off. Should I be spraying penetrating oil on the screw heads before removal?
2.) What should I do about the broken screwhead?

Ignor or totally remove the burner (Again, how to do?) and use an e-z-out to remove the broken screw and re-attach?
Your advice would be really appreciated! Thank you for the help!
LSchm