A lick is a short musical phrase. Licks are very common in lead guitar playing and can be created from any scale. The following lick is derived from the A minor pentatonic scale and makes use of both hammer-ons and pull-offs.
Here is a solo which makes extensive use of hammer-ons and pull-offs, Take it slowly at first and make sure all the notes sound clearly and evenly. Once you are comfortable with it , gradually increase the tempo until you can play it along with the recording.