I was surprised when installing mine, just how far my jack feet had to push on them before they snapped on. I did use the dish soap trick from the start but I just expected them to snap on relatively easily but they didn’t. It took a good bit of extending the jack into the snap pad before it snapped on. So if you’re trying to go easy on them and be gentle, I’d say don’t. Just extend your jacks enough that there is just enough room to slide a pad under, get on your belly and get them lined up right, then extend the jacks until you hear them pop on.
Also, do this one jack foot at a time. Don’t try to do all of them in one go. Too many variables at play.
If that doesn’t work, it’s possible you somehow got the wrong pads so maybe double check with SnapPad.