Floor pan

While I`m here a quick question............
The screws that hold the floor pan down, on both sides, are rusted as f**k.
I`ve bought new stainless ones to replace them and will have to grind the old ones off.
Do the new ones screw straight through floor pan like self tappers or is there a clip involved?

Theres a clip...you can buy them for pennies from the usual places..

Think there are small plastic clips but when I did mine I just bolted straight through instead

there is normally a red square plug that goes into the floor and large screws fit into them thru the top floor panels

Iyye thank yo`