I sure there is an easy answer but I'm stuck.
Any tips on how to get the bolts that run along the heater channels under pan.
There seems to be a heap of black crud all along there and can't get the socket onto the bolts.
So how do I get to them, please give me something easy LOL
I think who every had the car before has used different size bolts all the way along they don't seem to be 8mm

Bug is all gutted now, this and window removal all I got left before I lift the pan.

They are M8 which is the thread size, they should be a 13mm socket or spanner if original. The black crud will be some sort of underbody sealer, chip or scrape it off and don't forget to use a bit of elbow grease too

Thanks matberry, so wire brush and elbow grease, damn sounds like it's going to be a big job in a small space lol

Man up and get into it. I do this every day on UK resto cars, and 10 days to dissassemble a car is not uncommon. The sealer, crud, rust seized bolts, that can accumulate on old cars makes it real work. It is not like putting paper in a printer.