The means of abolishment would preferably be revolution.
But what kind of revolution does depend on the specific context. It could be a prolonged and gradual process leading to a radical reorganisation of society with little or no violence, or it could be violent revolution as in popular image.
These policies you said you would support are very characteristic of a welfare state
Indeed. There are both positive and negative aspects in a welfare state. Anti-discrimination law and universal healthcare would be among those that should be preserved in any decent society (albeit perhaps taking a more mutual aid approach like Abood mentioned).
the policies would quiet the workers and prolong the existence of such a state by preventing a revolution from happening wouldn't they?
It may. It may also give hints to the public that a government may serve their interests and decide to start participating more in the running of their affairs.
Wouldn't it be more in an Anarchist's interest to live in a rather repressive state, because only then would you be able to rally the people and to incite your desired revolution.
This has been a old leftist argument but is not necessarily true. Some of the more repressive states in fact have enjoyed quite long life - take either Iraq under Saddam or North Korea under Kim: highly repressive states could also lead to demoralisation and demobilisation. More fundamentally, it will be highly self-destructive for the Left to think and act in those terms.