Open up a photo program- if you have one on the computer- get the picture into it- go to "editor" and then to "resize" I ususally use a 1000 value on the longest side of the photo.
Then find the little icon for managing photos on the "go advanced" button here, and browse for the photo and upload.
OK,had to download some photo managing software,I think I got it now. I've also got a Fat Cat expansion chamber-$40+ shipping. I'm going 4 stroke and don't need these anymore.