How do I load a roll of paper onto the spindle on the HP DesignJet T520?

Remove the spindle from the printer and slide the blue paper stop off the open end of the spindle. Slide the new roll onto the spindle, ensuring the paper type is oriented as shown by the labels on the spindle, then push the blue paper stop back on until there is no space between the roll and the stops at both ends. On the T520, the blue hub should be on the left as viewed from the front of the printer when inserting the spindle. (Page 29-31)