how have you guys opened up your alignment slots for drop springs?

Just wondering how much removal is necessary and which direction I need to open them up in. Also, do you guys just open up the slots on the rear control arm adjustment slot or both?

I'm getting my new car with prokit springs aligned tomorrow. Also, is there any better-than-stock alignment specs I should use for the street?

I had the front end down 1.8" with the Pro-Kits on QA1 adjustable height shocks. The shop was able to achieve my prefered alignment using the stock slots for the front and rear bolts. I used:

Camber: -1*
Caster: +4*
Toe-in: 0.1

Seemed to handle well, with no unusual tire wear.