1) Accept your spouse's harm reduction goal--whether that goal is safer drinking, reduced drinking or quitting
It is important that you be accepting of your spouse's goal vis a vis alcohol--if you try to impose the goal that you think your spouse out to have upon him you might find that this backfires and your spouse's behavior gets worse than ever. Every action has an equal and opposite reaction. If your spouse has decided that what he wants to work on is safer drinking and you decide that you are going to try and make your spouse quit instead of drinking safely then you may well find that your spouse's drinking gets worse than ever.
Likewise, if your spouse is choosing to quit then it is not appropriate to tell your spouse that anyone can moderate and that moderate drinking should be the goal--when people choose to change then they generally know what the best change goal is for them at this point in time so it is important to respect it.
2) Don't try to make your spouse run before he can walk
Accept your spouse where he is at and be supportive of the changes which he is choosing to make. If he is choosing a goal of safer drinking then do not try to force him into a goal of moderate drinking right now.
If he chooses to have one alcohol abstinence day a week for the first month then do not try to force him to have six alcohol abstinence days the first month. Slow and steady wins the race.
3) Don't try to work your spouse's program for him
If your spouse has decided to cut back on drinking and measure every drink then your spouse has to do this for himself--if you start measuring his drinks for him then this will backfire and he may want to drink more than ever. Likewise if he is monitoring how much he is buying--he has to do this for himself and you can't do it for him.
If your spouse goes over limits then it is not your place to grab the bottle and dump it down the sink--he will just get another and resent you for it and perhaps stop trying to change at all. Let him decide in the morning that he has made a mistake.
The only exception to this is when safety is involved.
4) ALWAYS BETTER SAFE THAN SORRY--this is the heart of harm reduction.
Never ride with anyone who has been drinking before driving. And if your spouse has given you the car keys before he started to drink--then don't give them back after he is intoxicated.
5) Accept the fact of regression
Prochaska teaches us that slips are the norm when people change their behavior. For example--only one person in 20 quits smoking cigarettes on the first try. If your spouse is the lucky one who manages to change his behavior on the first try then hurrah!!
But do not become angry or backbiting if your spouse fails to change perfectly on the first try. In particular if your spouse chooses a goal of safer drinking or reduced drinking then if your spouse slips at some point, do not say "I knew this would never work and the only answer is to send you to AA and make you quit."
If you say nasty things like this your spouse my just up and leave. If he does not leave he may decide to stop working at making any changes at all since the changes which he has made are not appreciated.
Remember--if your spouse successfully moderates his drinking nine times out of ten then this is nine time better than if he never moderated his drinking at all.
6) Reward without patronizing.
Telling your spouse that you really like the changes that he has made in his behavior is a good way of rewarding him verbally. Of course food and sex are always good rewards too:-)