On the right hand side of the engine is a large bulbous item which is the air filter. The carburetor is located between the engine and the filter.
To properly clean it you have to remove it from the engine and disassemble it. If you have never done this before I would suggest that you get someone who knows what they are doing to help you.
After you gert the carb removed from the engine, remove the top of the carb body where the throttle cable goes in. The slide will pull out. You can just leave it hanging on the throttle wire.
Be careful and go slow. Remove every screw in the carb. To remove the float, grab the silver hinge pin with a pair of needle nose pliers and move it sideways, then the float will drop out along with the float needle. Note how the needle is attached to the float. In the center of the carb body is the main jet. Unscrew it.
Now get a can of carb cleaner at your local car parts store and spray clean everything. With the cleaner tube, spray into every opening. The cleaner should come out somewhere.
Reassemble everything. And you should be good to go.