How to update the new revised baseline to Actual?

Everyone,

I have just revised my baseline.  so the next step from my supervisor is to update the copy of the new baseline up to the data date(new Actual). since i already have an (old) Actual schedule updated on a weekly basis. so what i presume is updating the new baseline up to the data date with thousands of activities in one shot is hell of a work. so there must be some short cut way for scheduler to update it.  does anyone got some insights or similar experiance on that?

thanks in advance

justin