Advise pleas  phantom ( 4 )
I have my P 4. ND 4 filter.  By DJI   
I'm assuming it screws on but not sure  !
The diameter appease to be the same size as the Camera
I am  assuming the cover that is in place has to come off ???

I do not want to damage the gimbal.
Any help appreciated
   

The ND4 filter is designed as a direct replacement for the UV filter that comes fitted as standard.

You need to hold the camera body firmly , and the using three or four fingers grasp the UV filter and turn anti-clockwise, a pair of rubber gloves or such can help. But be gentle the threaded ring is quite delicate and if you grip too hard then it effectively squashes it slightly making it more difficult to move. When I fitted my ND filters (4, 8 & 16) I put the tiniest smear of petroleum jelly onto the threads, that helps make it easier next time. And just finger tight and no more is all that is required, the threads are very delicate so it's a good idea not to try and rush things.

Aardvark Posted at 2017-5-29 14:26
The ND4 filter is designed as a direct replacement for the UV filter that comes fitted as standard.

You need to hold the camera body firmly , and the using three or four fingers grasp the UV filter and turn anti-clockwise, a pair of rubber gloves or such can help. But be gentle the threaded ring is quite delicate and if you grip too hard then it effectively squashes it slightly making it more difficult to move. When I fitted my ND filters (4, 8 & 16) I put the tiniest smear of petroleum jelly onto the threads, that helps make it easier next time. And just finger tight and no more is all that is required, the threads are very delicate so it's a good idea not to try and rush things.

Yup got it.   
Thank you kindly.  

Aardvark Posted at 2017-5-29 14:26
The ND4 filter is designed as a direct replacement for the UV filter that comes fitted as standard.

You need to hold the camera body firmly , and the using three or four fingers grasp the UV filter and turn anti-clockwise, a pair of rubber gloves or such can help. But be gentle the threaded ring is quite delicate and if you grip too hard then it effectively squashes it slightly making it more difficult to move. When I fitted my ND filters (4, 8 & 16) I put the tiniest smear of petroleum jelly onto the threads, that helps make it easier next time. And just finger tight and no more is all that is required, the threads are very delicate so it's a good idea not to try and rush things.

Wrapping a rubber band around it is another way to loosen it. It provides the needed grip without pressing in on the threads.