Thinning shears. You can get them at beauty supply stores. As much hair that's in that wig, it would be incredibly difficult to accidentally hack off too much without working at it.
I have a half wig with a similar texture and I strategically cut out tracks a little at a time until I was satistified.Thinning shears would work also. Whatever method you use, be patient. You can't put it back if you cut too much too quickly.
I actually think it looks cute on you the way it is. But I feel you. I just bought a curly lace front that I want to wear to work. But its too big for the office; not conservative enough.