I need help with my research on handwriting digit identification using PCA

General information for the business: I perform research on handwriting digit identification using PCA
Description of requirements/functionality: I need help coming up with an initial matlab code I can use in my research. I can provide a data set and I need clear explanation of how each step of the coding does what.
Specific technologies required: Matlab Coding
Extra notes: Develop an automatic handwritten digit identification system using PCA and Use the kernel PCA with the Gaussian kernel and see if the performance can be improved. I need complete explanations on each step to make sure I understand the coding so I can use it for my own research, I can provide a sample data set provided to me by my advisor.