Has anyone changed a inner door seal before

[Mikeyd1]

Hi guys. Well I've noticed on my car there is some wear marks on my front drivers door seal left by the previous owner. I know I theory if i wanted to change the seal it should be simple but it's unclipping all the panels around it I'm not to sure about has anyone changed one before. Thanks

 

[c31561]

Here the "by the book" method of replacement.