You can do this
"This thing pops up so fast you have to get out of the way. I am pretty handy, but just recently started DIY on my bike. After my dropper tweaked out in a crash, was determined to install a new one on my own. How hard could it be right? I spent a long time measuring, ensuring I had the right size…instructions and videos were great. The installation was relatively easy but I took my time and I supplemented the OneUp videos with some on YouTube. Was mostly concerned about feeding the cable, and I was able to pull the new casing through the bike with the old cable, and double checked the length several times before cutting, but it all worked out great!"