Just drill a little hole.... (HELP)

[nosto]

While installing the solenoid/popper setup in my shaved door, I tried to follow the instructions that say "Drill a hole in the latch" so I could hook the cable up.

I _did_ manage to dull a new center punch and break 2 new 1/8" drill bits trying to drill through the latch (the part that used to be activated by the outside door handle). The bits hardly made a scratch.

Is this some kind of hardened metal?? Cast??

Is there any trick to drilling this stuff? Heat, maybe?

Is welding a small (washer shaped) attachment possible on this metal or is welding impossible, too?

Thanks,