General :: Sed To Replace First And Second Instance?

I might just be crazy or particularly dumb today but what I'm trying to do is have sed replace the first and second instance of a character on a line but not after that.

Basically it is a csv file with a date formatted as dd/mm/yyyy and I need to completely remove the slashes. No problem using:

Code:
sed 's////g' < file > outputfile

The only problem is that one of the columns after this may also contain these slashes and shouldn't be removed.

I must have read every single sed page on the net today to find a way to do it to no avail! Is it as simple as :

Code:
sed 's////1' < file > outputfile

And then run the same on the output file again? these two slashes will always be the first and second slashes in the file.