GPS convert from feet/inches to metric

I am on holiday in Spain and need to put metric GPS co ordenates in not feet and inchies as is asked for my the GPS - I know I can use a web site to work the conversions but I would prefer the GPS to be in the metric mode! Can anyone out there seggest how I can change the present mode? Andew

It is not possible to do it remotely. I have the software and a couple of days free, could you send a return ticket (will be happy to sleep on the beach) and I will pop over.