Jenk. It's all fairly simple. After removing the banjo nut and float bowl. Undo the big union nut on the bottom of your carb body No36.
Easier to slacken it while it is still bolted to the bike, but otherwise I hold them (NOT CLAMP) in a soft jaw vice between the flange and bell-mouth. With the nut off, you need to remove the jet block No34 through the bottom of the carb. These are sometimes a tight fit and soaking the carb in boiling water for 30 seconds will help. By holding the carb and a wooden drift with one gloved hand, you can gently drift out the block. I use a hammer shaft or piece of broom handle. Now you can clean everything in thinners. If you peer down the carb throat from the flange end, you will see a tiny hole. This quite often gets blocked with white verdigris. Poke it out with a thin piece of wire (bristle from a wire brush) Also the corresponding hole in the jet block. Blow the jets and drillings out with air and reassemble the block in the body by heating the body again. You will see a pimple on the block which you must line up with the cut-out in the body.
Remove the float and drop the needle out the bottom for a thorough clean and blow job! When you replace the needle, hold it up on its seat with a small screwdriver whilst you click the float into its groove.
Best to buy a gasket set before you start. I find Hitchcock's are by far the best firm to deal with and they sell genuine Amal parts.
Let me know if you need more help.
Ron
PS Nut No36 needs to be quite tight and easiest to do it on the bike before you tighten the float banjo.
PPS I alway check the flange for flatness by rubbing in a circular motion on W&D paper on a surface plate.....A bit of plate glass is fine. It's amazing how easily they become distorted.
Ron