D300: Clean Image Sensor - doesn't

I have a couple of pieces of dust on the low pass filter that won't budge no matter how many times I run the "Clean Now".
This is a crop of a shot showing the dust.

Is my only option now to manually clean the sensor? How dangerous is that, especially for someone with presbyopia?
This is a crop of a shot showing the dust.

Is my only option now to manually clean the sensor? How dangerous is that, especially for someone with presbyopia?