I guess many of us were waiting for this: the possibility to use Sigma's excellent…
How To Remove A Stuck Lens Filter (According to Canon)
Ever had a lens filter stuck on your glass? Craig Pulsifer had the issue and asked Canon how to do to remove the filter. Well, Canon's instructions on how to remove the stuck filter are somewhat brutal, but it worked. You need a hacksaw, a hammer and some more tools. Don't know if you want (and are able) to treat your precious Canon glass that way. However…
See the whole procedure with description on Craig Pulsifer's blog.
[via fstoppers]