The motor is a push fit into the bottom of the plastic washer bottle.
Your problem could be a blocked inlet - obviously - or maybe the pipe leading up to the screen is kinked or blocked.
Usually i pull off the pipe at the bonnet jet, and see if water spurts through.
John
Assuming the 106 is the same as the Citroen Saxo, only the filler neck is visible from under the bonnet. The reservoir bottle is beneath the inner wing, so its wheel off and plastic arch liner removed, offside.
John