for eppendorf centrifuge F-45-18-11 rotor top knob came apart

My top knob/nut for the rotor came apart because the inner ring came out if it's groove. Does anybody know how to push it back? I tried with a pair a curved jaw tweezers but it's hard to push it upside down inside the knob/nut after that goes over the rotor. It's easy to do it by hand in a detached knob but it will not fit over the rotor part after that because of the lip. here are the pictures to clarify the issue. https://drive.google.com/file/d/1Goncj7OVMX9ZYuBx1Zt3sBvp868V5pvF/view?usp=sharing https://drive.google.com/file/d/1KbrDWMN3-GLLzI0x-pmpNRgzdAK6a9Lj/view?usp=sharing Thank you, Adrian

Equipment: for eppendorf centrifuge F-45-18-11 rotor issue