How to fix this shifter grip pulling away from the shifter mechanism? Very old Specialized(02)

How to fix this shifter grip pulling away from the shifter mechanism? Very old Specialized(02)

Video Screenshot Gallery: Shifter Gripper Leaked

Day Bowman Shifter Video - YouTube
ST-R785 shifter leak? : bikewrench
How to fix this shifter grip pulling away from the shifter mechanism? Very old Specialized