I want to replace my bathroom sink with a utility sink but the plumbing drain pipes are smaller than the utility sink fittings. Do I have to cut them off ,they seem to be glued on very tight.is there an adaptor I can use .I have no plumbing knowledge at all(as you can see)and little money to spend. Can anyone help me please?

Most utility sinks rough in at 10 to 14 inches. Your lavatory roughs in at 18". Are you sure you have enough room to set a utility sink without opening up the wall and lowering the stub out? Cheers, Tom