I followed the technique outlined by Rick Higgins in the ‘Bug Me’ video (volume 6), but ended up cutting wider than was necessary due to be over cautious. I will trim up the cut next time and then chisel off the remaining metal that is tack welded to the tunnel.
As recommended by Mr Higgins I cut on the inside of the seat track. In theory the runner should now easily pop off using a chisel and a few swift hits of a hammer. Looking closer at mine I realised someone had previously repaired the area and reinforced the seat track with more than just a few tack welds! I shall purchase a suitable chisel and report back.
.....and the pan is out! I think I am going to hang onto this scrap metal for practicing my welding technique when the time comes.
Because my garage has no power I am completely limited by battery operated tools and my reciprocating saw was only able to cut out the drivers side pan before both batteries died. In fact, there was about 6 inches of cutting still to go, so I finished the last bit with a junior hacksaw (broke 3 blades though)!
So, one down one to go (and I promise not to leave it another 16 months before I tackle the passenger side!)