Whatever you do , don't dilute a ( guessing 40:1 ) mix with Seafoam or some other snake oil crap in an attempt to clean the carb..
Achto gives good advice in paying attention to the high / low speed Idle settings if so equipped .
Take a pic of the screws then turn them in one at a time counting the revolutions until lightly seated then write down how many for screw "A" / "B" etc .
Other than that , take some more pics ( if it's your first time ) , lay some newspaper out and DIG IN .
Let's see a pic and watch for serial numbers on the carb . Many times these can be had on E-bay for under 20 beaver pelts .
Sometimes it's just better and more economical to replace than rebuild .
Other advice which I have ...
The air filter should be rinsed with kerosene or some mild solvent then re-oiled and patted dry .
Fog the motor in the fall and empty the tank .
Buy the premixed fuel from Home Depot or wherever .
If not use Non E fuel and a name brand oil .
An ounce of prevention is worth a pound of cure and I'm not just saying that .
When I bought my house in '96 I bought the same Ryobi trimmer I'm using today .