You should start with theory first. Depends on the type of chord you want to solo over. Really, start with theory, get metronome and practise veeeery slowly!!!! Fast speed solos or playing is a secondary product of having very precise technique at SLOW speed. It might take months or even year. Just be persistent, stick to it and don't speed up tempo unless you can play the certain pattern without any mistakes and feel REALLY comfortable with it. Once again I have to emphasize: it will take some time!!!