How to process sentinel2 using sen2cor

[ABraun]

lveci has explained it quite nicely in another topic:

How to crop the images?

Cropping in SNAP is called subsetting. You can zoom in the image view to your area of interest and then right click to select ‘Spatial subset from view’ from the context menu. Alternatively you can select a product and then select ‘Subset’ from the raster menu. I would avoid using image formats like bitmap. For large images you can also export as BigTIFF which will give you a GeoTIFF file larger than 4GB but some other software may not support it.