How to turn baby diapers into diaper inserts

i have some pullups and i was wondering how to turn them into diaper inserts to make the diaper thicker

Without going into too much detail: What I usually do is tear the wings off, tear the leakguard and side elastics out, and cut a few slits in the back. Some people like to leave the leakguards and side elastics intact, but I find that uncomfortable. Then the diaper just scrunches itself into a wad. Or at least that's been my experience. YMMV!

I takes a razor blade and cut off the sides and slit the elastic and leg gathers every inch so it will lay flat. Then, i cut small slits of about 5 per row and a row every inch or 2. The slits are about 1/4 of an inch wide. I just poke the tip of the razor blade through to make the slits. Then, i shove 1 or 2 of these boosters into my diaper. The slits need to be big enough to allow liquid to pass through, but not too wide to allow sap to escape.

I do fairly much the same I cut the sides off then put slices in the outer cover and slide that in to a diaper, I leave the standing leak guards but that's because I wear depends and well we all know how well they leak..
I do some times use double sided tape on each side of the pull up or kids diaper and that helps contain and SAP that spills out from the slits and if I make them ahead of time I will use 3M spray glue to hold the diaper into the main diaper and set that aside to set

No need to cut off the sides, they will year off really easy.

I typically use baby diapers as my over night booster, and tear of the tabs this way too. I leave everything else intact and just insert it cupped over myself. When it gets soaked, the baby diaper just leaks into my adult diaper, so no need for extra slits in it too.

cut off the sides, get it down to just the matirial and put some slashes into it right down the middle.

I take the wings off the sides and make slits in the outer cover and leave the elastic and leak guards in place as a back up for the bigger diapers leak guards and elasticaci:

Why worry about cutting or slicing them?

Tear off the side wings, them come off easily. Or for that matter, leave them on if you want. When you insert it into your adult diaper, fold the tab/wings back so they won't press into your skin.

I don't bother with slicing their backing open either. When the baby diaper gets full, it will slowly leak on to your adult diaper. Slicing it open will just mean it will start leaking right away. By not doing this, you can extend the life and usability of your adult diaper by simply removing or replacing the baby diaper when it gets full. Your adult diaper is effectively not to used up to that point, and will last much longer.