Electrolux WE170V Service Manual page 68

Before securing the new blade insert a screwdriver beneath the tabs and raise
them a little.
Position the new blade inside the drum guides.
Push it towards the back.
Insert the screwdriver (in the central slot of the left-hand row) at a right angle
to the blade, so as to position it at the centre of the two drum tabs.
Tilt it towards the right so that the left tab moves upwards.
With the screwdriver still inserted in the slot.
Tilt it towards the left so that the right tab moves upwards.
With the tabs raised, the blade is secured to the drum.
Technical Support - DMM 68/80 599 74 98-60 Rev.00