Hi All
I have an Ico Sphere and need to move a point of the left side and have to “mirrored” on the right side.
Watching videos i see a lot of people splitting their objects and then applying the Mirror modifier.
How do I split an Ico Sphere that has so many points and Vertices?
Hello MajorNearMiss,
The ico shere is not ideal for mirroring. A UV-Sphere or a rounded cube have natural edges at the symmetry plane, so with an axis aligned view it’s easy to remove exaclty half of it.
That being said, there is one in the x-y plane 
And theer is: Enable symmetry in X Y Z axis (the butterfly like icon top right in editmode)… 
Short answer: You can’t. Use another sphere type or start with a cube and subdivide.
This works swimmingly 
Not really sure if this is what you are wanting to do, but, Add your iso-sphere, then knife the project and add your mirror modifier. Here I knifed an Iso-Sphere down to a quarter then mirrored it back into the sphere.
Hey Pte_Jack
It turns out that in Blender 2.9 there is a Symmetry tool that i can use to achieve what I need. So i dont have to split the Ico Sphere 
Glad you found a solution!
