Hi, I am new to this forum and hoping someone can point me in the right direction.

I am planning on doing Route 66 next year and an downloading the City Navigator North America rar file, for the purpose.
I will also get a suitable (Blank) SD Card

But I dont know what to do with the files in order succesfully load them onto the card. Formats, File Stucture, Other files etc.

I am pretty PC literate but could do with understanding the procedure and required software etc.

I would be grateful if someone could point me in the direction of suitable instructions.

Thanks Nick.