I'v e taken the freezer apart before for a plugged drain hole. Was hoping this was the same thing but it was not. Did some research for possible causes and came up with 2. 1- door not sealing and defrost cycle not working. The door seal could be it but I had not noticed the seal until after the ice started to b build up. So I went with option #2, the defrost cycle. Being a DIY type of guy (or wantabe) I checked out the web and the videos and ordered this parts.
I took pictures with my phone for the wire routing and zip tie locations, etc. Everything went just as planned except for 1 thing. The replacement sensor did not come with AL tape around it. I was able to peal enough (?) from the old one to cover the new one. Then got everything in place and put back together. The videos where a huge help. Don't forget the tin snips for the heating element holder on the right lower side.