PCA all Sentinel 2 bands, how to do it

Hi everyone, I’m new in SNAP and I am trying to do the PCA to all the S2 bands of an image but they have different numbers of pixels. I guess I have to rescale the images but I do not know how to do that neither. Can somebody help?
Thanks a lot.

You have to resample to same spatial resolution using:
Raster->Geometric ->Resampling
Optical ->Geometric->S2 Resampling Processor

Thank you very much, it seems to work