Valmar MULTY P TTi Series Handling, Operating And Maintenance Manual page 136

remove each scraper from the mixer individually (push the scraper
downwards until it jumps off the shaft);
Install new scraper on the mixer:
Hold the scraper with both hands and place the scraper to the holder and by
pressing it towards the spade (compressing the spring) the scraper is placed on
the shaft.
The scraper must lock onto the shaft. Please check, whether the scraper is
firmly attached to the shaft and whether it is placed correctly.
It is strictly forbidden to put plastic parts (scrapers) of the appliance into the dishwasher
to clean them!
Incorrectly and correctly attached scraper:
136