Keith
Did some early morning Googling and found the following explanation for your the GoPro LRV and THM.
What are .LRV and .THM GoPro files?
From the sound of it, you should be able to use these files on the computer by renaming the file extension to .mp4.
But they sound like low resolution companion files as explained in the link. If you have the high resolution file, I do not see why you would need them in a Premiere Elements project.
Please review and see if you come to the same conclusion. The need for non Premiere Elements matters may be something else.
Thanks.
ATR