[WindowsCentral.com]

All Lenovo Yoga Book's come bundled with a Wacom pen and three extra pen tips that allow you to try out both digital ink and real ink for real life paper. Changing these heads can be a little tricky, so we've written a guide to help you along the way.
How to remove a pen tip

[LIST=1][*]Take the Real Pen cap and place the current pen tip into the hole at the top of the cap.

[*]Tilt the pen lid slightly until you cannot tilt it anymore. Don't force it, or you may damage your pen tip.
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Full story from the WindowsCentral blog...