Super easy. I did it in my garage with a wrench and jack.
First thing I did was crank the truck and get the bags in their highest position. Turn off truck and get a jack under the frame to where it will hold the truck up while you take the bags out. The vehicle will not fall on you. It will hit the bump stops if the jack fails, but you could always use some tall jackstands if it makes you fell better.
Next, I removed the air line from the compressor. The bags will deflate, but the jack will hold the truck where is previously was. Remove one side and install the new bag. Repeat for the other side.
If you haven't done so yet, install the spacers on the airbag sensors. This will tell the truck where the bags need to inflate to.
Once you have them installed, bolted, and plumbed, remove the jack. The vehicle will be resting on the bump stops. Crank it up and they will inflate. You will need to cycle the suspension. You can adjust the spacers to your desired ride height. DO NOT ADJUST THE ACTUAL SENSOR, ONLY THE SPACERS.
When everything is buttoned up and running, spray some soapy water on the new connections. I had to fight a slow leak on one of the new push-to-connect fittings and ended up destroying it. If you need more here is the link to some new ones. I also keep these in the truck just in case.
https://www.amazon.com/gp/product/B0BJQMDC94/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
Good luck! It really is very easy.