On the staff front - it is probably a combination of reducing the number of trains running (possibly by making those that are, longer) and bringing staff terms and conditions in line with similar non-rail industry jobs. Unions shut the who thing down for months? On the new leisure railway, is that going to be apocalyptic? - probably not. Taxpayers funds shouldn't be funding some of the current terms and conditions and productivity rates, which are out of step with those pertaining in outside employment. Cutting infrastructure costs would probably involve slowing secondary services down , removing track no longer needed due to service reductions etc I would think.
The railways don't have some kind of right to exist - funded no matter what. I know some railway employees and enthusiasts won't like this, but the industry has to work out how to remain relevant (or regain relevance) to the majority and keep costs in check relative to revenue. That does not necessarily mean being totally commercial, but there is no blank cheque, nor should there be. Fortunately there are many in the Industry who understand all too well the landscape unfolding, but there is no room for complacency.
As for achieving relevance, and keeping revenue/cost balance in check, look at the railways of Argentina, some of the Balkan States, South Africa and various others to see what happens when you don't.