Tips sought for editing of routes

Sometimes I want to edit a route I've made, and I just end up in a muddle. The easiest way to explain is with pictures, so in my "before" file, I wish to remove the loop with waymark 14 and send the route down NCR 52, but I just end up in a mess with spurious spurs and loops as the "after" file shows. I'm sure its operator error on my part.

Could somebody please explain how to graphically edit routes properly please?

Thanks, Graham