Shoot the ones far away first. If I am not wrong, you are in the level of the Valkyr laboratory, right? I am sure it is by shooting the laser mines, just start with the ones far away and start opening a path to jump over some lasers and shoot and...stuff. I think you have to jump to a point first, then shoot. I really don't remember that way, but I got it the first time, it was preety easy.

Care to post a screenshot?