Tripowin C8 cable - MMCX 3.5 mm

Bought the Tripowin C8 cable for replacing the stock cable of Sennheiser IE 200. However, the MMCX connector is not having a close fit with the Sennheiser unit. Somewhere I read the red and back rings at the end of the Tripowin MMCX connection can be removed for a snug fit. Any one can help on this to sort out this issue.