In the Builds, Tuning & Modifications section, there are two different approaches to improving the cooling of the Lawmate VTx, one simple, one more challenging. I did the more challenging approach. I discovered a few things along the way that might help out.
First, don't remove the SMA connector. It's a pain to solder it back on the case. I discovered that the center pin of the connector and the plastic around it can be pushed out of the SMA housing from the back side. I didn't get to try this, but it is probably a simple matter of heating the solder on the center pin while pushing on the plastic to move it off the PC board.
The second thing I noticed is that, in the TBS instructions, there is a copper heatsink glued to the bottom of the PCB. In my case, there was no heatsink at all! It was just a blob of solder. I'm guessing they've changed their manufacturing process? I cleaned it off and cut out a piece of copper from an old video card heat sink that fit perfectly. Soldered it to the PCB and applied Arctic Silver, as instructed.
When it came time to close up the case, I thought about the alternate "simple" mod on the TBS web page, which was to use heat transfer glue to attach a copper heat sink to the top of the chip. Instead of doing that, I cut out another piece of copper (it just happened to be the right thickness) and soldered it to the top of the case. Instead of having to mess with glue, I just had to apply more Arctic Silver to the top of the chip and I was done. One thing to be careful of is to leave a little bit of a gap where the copper meets the side flange of the top of the case. (see the attached picture) That gives clearance when you attach it to the bottom of the case. So now, the chip is sandwiched between two pieces of copper connecting it thermally to the top and bottom of the case. I'm planning to move the external heatsink to the bottom of the case, as with the "challenging" approach, since there is more surface contact with the case, and I suspect the PCB was designed for the heat to transfer off the chip through the bottom.
Hope this helps!