How to remove motor and pump stuck in borwell 90 feet deep?

We recently drilled a borewell of 90 feet and have installed a submersible motor and pump ( motor 0.5 HP) through 1 " HDPE pipe. We were advised that we need to keep the water running for a few days to get clean water.

Of late, we have observed that we get water at full flow for 15-20 minutes and then it becomes slow and the water quality also changes from clean to muddy. We were advised to remove the pump and clean the motor.

Now problem is that we are not able to lift motor and pump even after using compressor flushing. (there is pvc pipe 4" casing up to 70 feet ) and motor is at around 70 feet. We tried to manually lift the motor but not able to remove it since it is stuck in the mud or something else.

At present both the motor and pump are working normally but water is not clean plus flow goes down after some time.

Please suggest how to lift the motor and pump from the borewell to clean and reinstall it. There is chance that since it is a 1" pipe of HDPE we might break it while pulling it out forcefully.