Use a simulation

http://frog.edschool.virginia.edu/Frog2/Dissection/Incisions/muscle1_first.html

This website prepares students for a frog disection. It explains the theory step-by-step and then uses simulations of a frog so that you get it correct at each stage. By doing this, it prepares students so that they have more of a chance of getting the practical correct and therefore improving skills. Also, computers interest younger children more - they are more willing to learn via a computer. Also, schools can use this as an alternative to using actual frogs as this may cause controversy within a class - some may not feel it is right to cut up a real frog. Furthermore, if this happens and an alternative is suggested like learning from the book, this appeals more as you can still actually do the disection but with a virtual frog instead of a real one.