I'm still working throught using Homeport with my Garmin 78SC. I am able to create a route and send that route to my 78SC. But, if I want to create a second route I haven't figured out how to clear the first route from Homeport. Thanks for any help. Being a novice at Homeport has some frustrating moments.
There are several ways to deal with routes but one is to right click on it and select "Delete".
As you become more familiar with HomePort you will learn how to save routes in folders and move them around. It's a shame there's no actual manual but HomePort is pretty versatile once you get used to it.