The carburetor is a particularly delicate component, which is why it is necessary to dedicate some attention to it. It is essential not to leave fuel inside, which, by stagnating, ends up spoiling the membranes. There is a specific pump to be attached to the "beak" where the fuel inlet pipe is connected to completely empty the carburetor. If you don’t have this tool, the carburetor may be shaken gently so that the all the fuel escapes.
If, however, you wish to do things properly, you can once again rely on Dr. TKART for how to disassemble and reassemble the membrane carburetor.