Rather than being clamped on the extruder release screw, this button is attached to the idler arm with the provided screw. It never falls off or wiggles in place. The button is quite grippy due to the ridges at the top.
It works perfectly together with Anet A8 alternative 40mm Extruder Fan Mount.
If you print one, please consider posting a make. I enjoy seeing things I designed out in the wild.
Print it with 2 perimeters to save some material.
Step 1: take the screw out
Use an M4 wrench or pliers to release the nut and take the screw out.
Step 2: insert the screw into the button
Take the nut off of the screw and insert the screw into the button. It's a very tight fit so most likely a hex screwdriver will be handy.
Step 3: attach the button to the idler arm
Screw the button to the idler arm and use a hex screwdriver to tighten it.
Congratulations, you can now change filament without hurting your fingers!