Break it up in smal sections. Lets say that the solo is about 30 seconds long, divide it in 10 sec. It lot easyer than to learn it whole at once and by the way, when you are at the end you´ll probably will forget the beggining.

But I´m not a right guy to tell you how to learn a solo actually ´cause I never do it. I usualy learn it so it sounds "somthing like that" wich means lots of own stuff combined with orginal. It makes it more fun to play afterwards and lot easyer to learn and develop my own style.