I think you click on the icon that looks like a mobile phone in the "Route tools".

By clicking on that icon the gpx file is downloaded to the downloads file on my p.c. But I can't see how to then get it to my Garmin device. Any suggestions welcome. G

I've not tried it on an eTrex 20 (I have an older Legend HCx) but I think there's two ways to do it. You can use Mapsource, which comes with the Garmin; or you can manually copy it onto the GPS. To do the latter, you put the GPS in Mass Storage mode so it appears on your computer like a memory card; then you copy the file across so it sits inside a folder called GPX, which should in turn be inside a folder called GARMIN.

Thanks Richard I'll give it a try. G

I can copy it into the GPX file - but can't find on the Garmin unit in order to use it. How/where do you find it on your Legend unit.? G 

I have a Garmin Edge Touring.  With the GET you open up the garmin folder on your machine and put the gpx route into the New Routes folder.  Disconnect and switch the garmin back on.  It should then have loaded into courses. 

There is a glitch in that the course may be called Active route rather than whatever you called the file and it loses its date, so you have to rename it on the garmin.  This seems to be a recent problem as older routes I downloaded from CT were fine.