Get yourself a chemical dictionary, dimethylbenzene is commonly known as xylene, methylbenzene is commonly known as toluene
Hardy synthesized toluene from benzene and chloromethane via the Friedel-Krafts synthesis in
JSCI 67 81 (1948)
These solvents are easily obtained, there's probably no need to demethylate xylene to obtain toluene when you can buy it cheaply, questions such as these belong in the newbee forum