Foam rolling or SMR ( self myofascial release) is a wonderful technique to perform myofascial release around muscles.
Using this piece of equipment you can improve your flexibility and reduce injuries.
All you need to do is roll along your muscles as shown on the video feeling for trigger points which then you can roll on a little bit more.

Look for your foam roller at your health club or you can purchase one at a health equipment store.
Happy foam rolling!