HP15C reset loose heat stakes

[Zoobala]

I have a couple of keys (SST and R/S) that rattle on my 2509A unit. I removed the back of the case and inspected the PCB and heat stakes. There is a little give if pushing on the PCB on that side of the case, and a little pressure exerted on the PCB can generate a little space between the head of the heat stake and the PCB. I'm wondering if there is any advice on how to apply pressure while re-heating the stake(s) to make the fit more tight. Also what to use to heat the stakes? Finally, the unit works just fine and I don't want to muck it up. So if I should just leave it alone, that's fine also.