I like Tomaszjr's solution but haven't found it for less than $20.  Blasphemy, I knowww, but the Ubiquiti U-PRO-MP stainless mounting bracket comes with said "t-bar scissors" for $8.50.  I haven't found a lower-cost solution to get the GR-12 on a drop ceiling PROPERLY. Recycle the bracket, use it as a template for junction boxes, or save it for a rainy day. ... View more