Sometimes if code is not made available to download it must be transcribed or copied (I prefer the select content, crtl-c (copy), crtl-v (paste), route. However sometimes the code must be decoded due to the way 2-D math is interpreted when it is copied to Notepad.
For example,
a:=(x,t)->5*x+3*t*x^2
in Standard mode looks like a := proc (x, t) options...