They should feel relatively heavy for their size and have a slightly sweet smell. Store at room temperature for 1-2 days or place whole into a plastic bag leaving top exposed and store in the fridge for up to 3 days. Slice off the top and base of the pineapple then stand on a chopping board. Slice away the skin in strips then cut the pineapple into quarters lengthways. Cut a thin triangle from the centre of each quarter to remove the woody core then slice or chop as required.