We don't spool reels here, but you could buy some backing and just spool it at home. Or you could always head to your local flyshop and have them do it (remember to buy a couple flies from them as a thank you).

If you want to spool it yourself, below is a link for backing. Also, switching which hand to retrieve with is a quick switch with this and most reels.

http://www.backcountry.com/scientific-anglers-fly-line-backing-dacron