There is a how to on bearing changing on this site,
http://www.masportaviator.com/
bearing are likely the same for any OS 40 or 46.
All the how to stuff here is a must read for a new flyer IMHO. Save it to your favorites for a reference.
The SF series is a winner. I bought one for a buddy on Eba^ NIB reasonable. He has flown it for three years so far.
This is the parts list. OS has discontinued it but there are still parts out there new. Eba^
http://www.osengines.com/parts/xr15420.html