I read the sticky
my ecu looks like the one in the picture (mine 99 I30)
except there does not seem to be a clearly visible screwdriver "slot" ,
that is when you look at the hole where the slot is supposed to be I do not see a neat screwdriver blade hole- looks like I am looking thru the bigger hole (1/4 inch round) and seeing a piece of white foam inside.
I am scared to mess it up - are there any other pix online of these things or do I just stick in a big screwdriver and turn

Help

 

The 99's have a plastic screw. I think it may be philips rather than normal. I think it works the same way, but I'm not certain. Autozone will check for free if you'd rather.