UPDATE: as form user suggestion additions:

• increased lever lenght for easyer use.
  -added space washers to improve bearing movements.
• slightly moved the ptfe tube 0.5mm for easier use
  -mooved the spring hole 1mm

this is a modifcation of one of my old works, changed the lever to fit a standard creality feeder.
improvements:
-ptfetube on the on the filament entry in order not to make the filament touch the threaded rod, u can just curve it a bit and it's ready.
-more solid lever, with two plastic parts, and a longer nut
-adjustable spring for pressure control, the original one isn't great in many cases, using the little plastic nut and the lever without the bolt, will be the same as the original one distance.

things needed:
m4x10mm bolt for the bearing (original one is shorter)
m4x20mm+nut for spring pressure controll.
for the other parts u can use the original nuts.

mounting:
1-force press the lever and cup togheter. insert the bearing and screw the nut in the plastic, check if the bearing spin without problems.
2- cut a piece of ptfe tube, I sugest not les than 30mm, force press in the hole, and u are done
3- force press an m4 nut in the spring controller, and then screw the m4 bolt
4- mount everypart, than put the pring with the cap in the feeder
:)

printing:
suggested material: petg or abs
infill:40% at least