1) Thoroughly clean the glue wheel using a damp sponge and the tool provided.  
    There is a special sponge for this in the printer accessory kit. 
    Pay special attention to the area between the wipe and the glue wheel.  
2) Release the pressure on the glue by opening and closing the top of the glue bottle. 
3) Turn off the glue at the switch just below the glue bottle.  

Optionally.  (To save energy) 
4) Shut down the printer controller using the item in Settings/Power and shut off the mains power.  

These actions will minimise any problems you might encounter when you go to use the printer again.