I fitted rivnuts to my
solar panel when installing it on the Moho.
I only had 10 rivnuts to set so decided I'd use a bolt and nut as suggested by QFour. It didn't work well for me because the nut, when driven against the head of the rivnut, caused the rivnut to rotate despite the fact that the rivnut is longitudinally corrugated and a tight fit in the holes I drilled. I tried a couple of greased washers between the nut and rivnut but still had a problem.
I gave up and made a simple tool from a piece of bent scrap stainless steel strip, a bolt and some washers:
View attachment 83914
The bolt head (top of the image) has a couple of star washers either side of the strip and is prevented from turning relative to the strip by tightening the upper nut.
The bolt passes through an elongated clearance hole just below the driving nut (it needs to be elongated to allow the strip to flex as the driving nut is tightened).
The driving nut (bottom of the image) has a couple of greased washers under it and it rotates against the strip,
not the rivnut.
In use the bent strip can be held in one hand and the driving nut turned with a spanner.
It works really well:
View attachment 83915
.......... but if I had more than 50 rivnuts to set I'd buy a purpose-made tool!
I hope this helps.
Colin