2d crank nicolson heat transfer

so I have made a 1-d heat transfer PDE solver using the Crank Nicolson method but I'm not sure how to implement a 2d version of this method for the heat transfer between to parallel plates of equal dimensions.

I have also attached my 1-d code for reference

[John D'Errico]

Don't expect an answer. Your question would require a great deal of time invested to give any intelligent answer, and essentially require someone to solve your project, since you have done nothing but show a solution for a different problem.