help w/ wheelchair track screw removal

[MeasureThrice]

Hi all! There are 4 wheelchair support tracks on the floor of my short bus (see photo 1, right side). The 1/4" finely threaded screws are inlaid in the tracks. I've tried leaving WD-40 overnight (twice) using a hex driver and an impact wrench and they're not budging. I haven't used a screw extractor because (1) the hex driver fits (no corrosion or damage to the screw head itself) and (2) the screw is not spinning (aka it's not stripped). I'm assuming the screw ends and bolts I see underneath the bus are the ones I'm trying to remove (see photo 2). Using an angle grinder on the bolts doesn't seem like a good idea since I can't get a good angle to grind/cut efficiently, plus the tool can't reach most of the screws. Can anyone shed some light? Thanks much!

 

[BarnYardCamp]

My bus had those as well. I used a circular saw with the blade set almost deep enough to cut through the rubber mat and the plywood flooring.(refer to other post about floor removal) Then I pried up the plywood flooring. This left the wheel chair tracks. I discovered that there is a rubber gasket between the tracks and the metal floor. I used a sawz-all with a metal cutting blade to cut under the track, basically cutting out the rubber gasket. Once I had a couple of the bolts cut, I drove a wedge under the track which made cutting the next bolts easier, moved the wedge along as necessary. The cheapy sawz-all blades only lasted through 4 bolts, the more expensive 8 to 10..it was a lot of work as my bus had bolts at about 4 inch intervals.
The sawz-all blades were medium length and flexible enough to bend while sawing leaving hardly any marks on the metal floor.
Hope this helps.

 

[MeasureThrice]

Having access to the photos I was referring to might help Here they are! ...

 

[MeasureThrice]

My bus had those as well. I used a circular saw with the blade set almost deep enough to cut through the rubber mat and the plywood flooring.(refer to other post about floor removal) Then I pried up the plywood flooring. This left the wheel chair tracks. I discovered that there is a rubber gasket between the tracks and the metal floor. I used a sawz-all with a metal cutting blade to cut under the track, basically cutting out the rubber gasket. Once I had a couple of the bolts cut, I drove a wedge under the track which made cutting the next bolts easier, moved the wedge along as necessary. The cheapy sawz-all blades only lasted through 4 bolts, the more expensive 8 to 10..it was a lot of work as my bus had bolts at about 4 inch intervals.
The sawz-all blades were medium length and flexible enough to bend while sawing leaving hardly any marks on the metal floor.
Hope this helps.

That totally helps. Thank you for sharing your experience. It's especially helpful to now know about the rubber gasket.