Anyone Replaced The Front Sprockt On T120 W/c?

I would like to check the front sprocket but despite refering to the Haynes manual I am perplexed how to remove the rear brake master cylinder. There are numerous screws/bolts but can't figure out which are relavent
Any advice would be gratefully received.

Cheers JB

 

Ok, I've sussed out which bolts release the footrest assembly and I've bought a new 36 mm socket and having freed the tab washer I had a go at releasing the front sprocket nut.
Would it shift? Would it hell.
With the bike in top gear and the dear lady sat on the bike and the rear wheel chocked with a piece of 2 inch dowel, I applied the socket with about 18 inches of leverage but still no joy. I applied the heat gun for a few minutes still to no avail.
I'm not the strongest guy in town and I know that it will need a fair bit of force to break the 180nm, but I am stumped.
Any suggestions?

 

Thanks Capt,
Unfortunately you have to move the rear brake master cylinder on the 2016 T120 to get access to the gearbox sprocket. Clever.
However I will try a longer lever.
JB