For 1100/1150 models I read so much bollox on how to do this simple task. The pictures were taken with the oil drained during a service. But you don't need to drain the oil to replace the sight glass, just lean the bike over to the right and lean it against something, or have some support it. And another thing, the window isn't glass, it's plastic. So here it is in pictures, and it'll take you longer to read this than to do the job. Tools needed - old screw driver, hammer, seal puller or other hooked implement, 30mm socket and extention. You want a 30mm socket because it's the same diameter as the sight glass. New sight glass, front view. Rear view. Hit screwdriver into plastic face, not to hard, you just want to break it. Hook the seal puller, or other hooked implement into the edge of the sight glass . And lever out. What you have when the sight glass is removed. Carefully insert the new unit with your fingers just so it stays in place, then use the 30mm socket as a drift, tap the socket extention with the hammer to fully locate the new glass Job done in two minutes if your slow.