CONFUSED! (Base camp map installing)

Former Member
Former Member
Hi there, I have recently purchased a Garmin Foretrex 401.

After downloading BaseCamp I have noticed that the bog standard map is not detailed enough for what i need it for.
I have downloaded a free map with contours etc and am tryingto "link" it with basecamp so I can at least plot my waypoints accurately, before sending the waypoints to the foretrex.

The map i have downloaded is a: 130712-British-Isles+Contours-Routable-GMAPSUPP .img file
there was no .exe file within the download package and you tube is next to no help!

can somebody tell me where I have to "drag" this file or some steps to manually install so that i can start using my foretrex to better effect.

Cheers

Ben