I believe all the stores now have 1.006, yes download it again from the store you bought it from. There is no need to remove the previous install. If you have made any customisations, like adding new repaints or anything like than, you will lose them if you do not backup the old files to a safe location, put them in a folder on your desktop or somewhere like that, as the new installer will wipe everything out that is currently within the Majestic aircraft folder structure.

Ok thanks for the info Andy....