I did mine myself years ago. I used a knife and cut the existing bags in a spiral in line with the spring and pulled it out like an orange peel. It was 7 years ago, but I don't remember removing the spring or anything, just stuffed them in there with lots of soapy water.
Put them in there, then inflate, then drain them, then inflate again. That gives them a little "re-set" in case you got them in a little crooked the first time.
I don't think you'll die driving around without them. It's just more bouncy, and you can bottom out the suspension on a hard compression. Since you've never had them, you don't even know how much better it will be. Personally, I barely noticed the difference. But mine was a 1982 280 Excella.
Good luck! Wear gloves and save your knuckles.
1996 Airstream Excella 28'
2007 GMC Duramax 4x4 CCSB