I often need to add references to a citation. Paperpile doesn’t reformat the citation. ie-if the formatted citation is  and I add another two refs, it formats as  instead of [2-4]. I have tried editing the unformatted citation by removing brackets, but this seems clumsy and not general for different citation formats. Is there an easier way to do this? Also, is there a way to unformat citations?
Please have a look at this thread about multiple references within a citation:
Just click ‘Edit citation’ and add citations using the dialog.
At the moment there is no way to “unformat” the citations, but it has been requested before and we think about including it.
It depends upon Site. Because some sites allow edit your old citation listing but some sites not allow edit.