> Can I just get access to make changes to the sandbox or
> do I need to ask for the changes to be made and someone
> else with more authority than I will do it?
> I'm happy to make the changes and commit updates if need be.

http://www.boost.org/community/sandbox.html says:

Anyone interesting in working on Boost code is welcome to a sandbox developer account; see the instructions on the BoostSubversion (https://svn.boost.org/trac/boost/wiki/BoostSubversion)  wiki page.

But I don't really have the "authority" to answer your question. I guess if it is just for a single commit, it would be better to mail the output of "svn diff" or of TortoiseSVN->"Create Patch...". But if you are "interesting in working on Boost code" on the other hand...