So got the Eastwood kit and added the lever type puller as the photo shows;
The tip in this adapts to a mig and you have to do a bit of experimenting because too far up is bad and too far down is also bad so it has to be somewhere in the middle.
This is an example of putting it too far up but I didn't do that on purpose. it was just where I started.
This is probably a good time to mention that there is nothing but the mig wire holding that stud in there. If you try to stick one of these on a downward angle which I did, it will want to just fall out. I think the tube needs a tiny spring in there so you can get some push to set it against the metal. It is difficult to get the stud to stick inside a hole like I had to do.
I decided to try this for my first stud weld challenge. It is the passenger side low corner of the firewall just next to the tunnel. It looks like a hit from somebody trying to slam an engine and probably transmission into the thing and not really caring a whole lot if they banged up the firewall or not. This is not how I do things and its probably good that I will never meet the car owner or mechanic that did this.
Stud placement obviously is critical and you may have a tendency to just stick one right in the middle of a dent but that is generally the last place you would put one. I decided to put them in a triangle inside the somewhat circular dent. I wound up pulling a bit, re-positioning them and pulling again as the metal came out. I think this is the normal way that this works. The photo below is my second positioning of the studs after pulling the deepest dent up some.
A side note on these things. If you stick one to thin metal, it is likely that you will pull a hole when you are trying to pull the stud. I did that in one place and I wasn't really pulling that hard.
This tool worked really good. I wound up not using the slide hammer but on one stud toward the end.
Not finished with it yet but it looks a bit better I think. My firewall is horrible. Most of the small stuff will disappear under here though with black epoxy primer and satin black engine bay paint but I thought I should pull out some of the larger obvious dents.
I did all this sitting on the concrete inside the engine bay. This is not a happy place to be sanding, grinding and welding but I don't have any sort of rotisserie yet to do this stuff on.