As a first time poster, maybe you need to be informed as to these facts:
1) we are all volunteers here;
2) we have day jobs;
3) not everybody reads the group every day;
4) patience is a virtue.

You may wish to try bleeding the system before replacing things. You might
just get lucky and the pedal will firm up. Bleeding is identical to any
other hydraulic clutch system (or brake system for that matter).

As for your upper left MC mounting nut, both nuts are removed from under
the dash and no dash disassembly is necessary.

You'll just have to find a way to do it, even if that means modifying tools
with a torch and grinder to get them to fit. Using U-joints on your sockets
will help, too. Try really small wrenches, or a 1/4" ratchet set.

You will have to adjust the new MC pushrod after installation.