I'm not familiar with this conversion and thought it was a drop in type system. What needs to be staked? What ever it is, you need a punch that is materially harder than that which is to be punched and I doubt a phillips head screw driver would be sufficient. I have used concrete nails in a pinch, nail sets will sometimes fill the bill.
Robin
It is pretty much drop in. But, the gas block (key) has to be staked to the BCG the same way putting an actual gas key would have to be. The block is made of 7075 aluminum just like any other gas key, so a screwdriver will work. My thought on using the phillips is it's more like an actual punch than a flat head. Or a nail could do the trick as well.
It’s amazing how much easier things go when you have the right tool. I did a catback exhausting on my son’s car with him and I couldn’t get the exhaust hanger off. I tried for about 30 minutes and then googled it. They make a tool for it, I sent the kid to the auto parts store wheel I worked on other things. Took 2 minutes to get it off with the proper tool.