The Micro SD card could be an easy way to do it but I've never had a phone with a card slot so have no idea on how this works in practice.
I got my Touring in 2015 and it's worked pretty well, the turn by turn is good when it works but often glitches (especially on out and back routes) and doesn't think you've done a certain direction so the instructions never progress beyond that point. It's easy enough to follow the line on the map without all the directions when this happens.
Some of that could be the route files / map set I'm using or it could just be a buggy Garmin.
The on-board point to point routing is terrible, it creates very convoluted routes that don't make sense.