I have the same challenge with getting the mainspring back into my P-07. I personally would not want a lanyard loop poking out there, since my magazine loading method includes giving the base of the grip a smack with the palm of my hand. I also wouldn't want to use something made of metal to hold that plug in while reinserting the pin, since that would probably scratch or otherwise damage the plastic plug and/or the base of the grip over time. So I use a small wooden peg that is maybe 3/8 inch to push it in. In my case I took the round end of a wooden chopstick and cut a piece off of it with my dremel, then I sanded both sides of it flat. So I can put that on my rubber cleaning mat, push the grip down onto it, insert the pin... done. Before that, I used to use a piece of eraser cut off of a #2 pencil, but I was crushing those flat on a regular basis.