Screens are fairly easy to replace, but sometimes a small local repair shop works out to be not much more than doing it it yourself. The labour charge will be low and they may get a better deal on the screen than you can so I'd get a couple of quotes first
If you do decide to do it yourself take the old screen out before you buy a reaplcement, if you can't do it or are uncomfortable as you go along you can bottle out and take it to the shop!
Normally it's a case of removing 4 screws which are hidden by small rubber bungs, which you pop out. That allows you to remove the casing, after that a few screws holding the LCD in place and a ribbon cable should see you right!