Assuming you have already disconnected the choke linkage, the only thing holding the two carburetor halves together should be these six screws:
The screws can be removed with a flathead screwdriver and are part number 64695.021 (previously 64700.001).
These carbs have a little ID tag under one of the screws:
Six screws removed with associated washers:
Screws and choke linkages sorted:
Now the top half lifts away to reveal the insides of the bottom half. The gasket has stayed with the bottom in this instance:
The top half, now removed:
Gasket moved slightly so you can see it more clearly:
Gasket removed:
Now you can move onto the next step of removing the floats and needle valve or go back to the main Weber 32/36 cleaning/rebuild page.