the "dynamics" package and numerical solution of DEs



I'm trying to run rk on an ODE, and the manual says to load 
("dynamics"); but maxima can't find the file in the share folders.   
Any help where I can get it?

I want to solve an ODE in 3-space numerically; that is, I want to  
integrate step by step from a given initial vector.  How can I get an  
education of the options for such a task?

Thanks