Eton habitation door lock cover - how to fit

I have a recently purchased 2006 Eton and the habitation door lock cover has split. I have purchased a replacement kit from Auto-Sleeper at a significant cost. I now have to fit it. Has anyone here had to do the same task? I would be grateful for any help, guidance, tips instructions etc. Thanks Mike

I think your door is a Dometic CaraD_Rplus. Page 8 of this pdf gives instructions for replacement of outer lock cover.

https://www.reimo.com/de/bilder/intern/ersatzteile-daten_2012/dometic-seitz/product-documentation/data/Rep%20CaraD_Rplus_EN.pdf

Thanks Peter the information you have provided is very helpful. I'm extremely grateful. Mike