From @cheershendtco on Wed Aug 31 2016 03:39:25 GMT+0000 (UTC)
So in effect objects added to ipfs cannot be deleted or edited. If an edit is required the file(s) must be edited locally and re-uploaded to ipfs, generating a new hash value for the file(s).
If I have uploaded files with my PC, and how to manager these files with other PCs?
Copied from original issue: https://github.com/ipfs/faq/issues/169