In terms of numbers, or cost of compliance, or what? Anything would be good, really, but I think the best way to do it is to:
1) Issue an EO repealing all regulations and EOs since the election. Then,
2) Order all regulatory agencies that they can keep 1 regulation for every 3 they discard (and no new ones).
By the end of the year, that second order should say, any agency that hasn't met the target will be forced to meet it by having the first 3 of every 4 remaining regulations repealed. If you want a more orderly process than that, better get on it.
UPDATE: Following that, issue an order that the remaining 1 in 4 regulations go before Congress for an up-or-down vote, after which they too will be repealed. The ones Congress likes will become laws, and so won't need to be regulations. The ones they don't, well, we'll just have to do without them.
In a few easy steps, you'd recapture the legislative authority for the Legislative branch, and make the environment for new business in America better than it's been in a century.