You can cut the plastic away. But, for me, it's easier to turn it upside down and tap it on the edge of a counter, porch, deck, something that won't squash the leaves, and allows room for it to come out of the pot.

Put some of your potting soil in the bottom of the new pot that will be its new home and tamp it down.

Put the plant in and see that the top is at about 1-2" from the top. You don't won't to put soil above the original soil line. You want it to be at the same level it was in the original pot.

Then fill in soil around the sides, tamping it down as you go. Then water. If the soil on the sides sinks down a bit, add some more around the perimeter. Sometimes I add a little Osmocote (time-release fertilizer) to the soil mix, or you can fertilize it with super bloom afterwards to minimize the shock to the plant of being repotted. You'll probably notice that you won't need to water it as much as when it was root bound in the old pot, although peace lilies can grow in water.

Susan

Thanks Susan, he(?) seems to like his new pot.
J.W. Arndt

Here is a link that might be useful: houseplant aerobics

OH MY GOSH! How hilarious, but definitely a good simulation of what a spath does. I think you should post this in the gallery. There are a lot of questions about spaths, and it would be a really cool place to direct people who want to know about watering.

Susan

Thanks Susan. The file is over 600K, but I'll see if I can post it there.
John

Susan, The limit for images is only 60K, so I sized that animation way down to 57k, but when I tried to post it in the gallery, I got an error message that said animations were not allowed :(

Here is a link that might be useful: houseplant aerobics, again