Blur effect

[abobe]

how can i erase extra blur effect with eraser

[mecdos]

you can't. but you can make a clipping mask and mask it away. 

[Dave Creamer of IDEAS]

One option would be to place it as a linked Smart Object into Photoshop. From there you can apply the blur and edit the mask that is created. Keep in mind that placed vector art rasterizes in Photoshop, but it won't matter in this case since the blur effect will rasterize it in either program.