Kudos for nursing this long! You should be proud that you've provided for your son this long, but there's no shame in continuing to nurse him for as long as you're both comfortable. Curious why you want to wean?
You want to make sure you do it slowly if you're committed to weaning. You'll shock your body if you do it suddenly and could quite possibly end up engorged. As a Nursing Mothers Counsel peer counselor, we generally recommend to drop 1 feeding, then wait 3-5 days before dropping another to give your body time to adjust, but you only have one feeding to drop. I would try to cut down on the amount of time he feeds; ie: 15 minutes for a few days, then 12 minutes for a few more, then 10 minutes for a couple, and so on until you've weaned. If you son is still determined to nurse, it'll take a little longer. If he's ok with weaning, it could take a couple weeks.
You probably won't get engorged if you take it slow (depending on how much milk you're currently supplying), but you can use cold packs to help with swelling and express just enough for comfort. However, you do NOT want to take a hot shower as heat keeps the milk flowing. Try to keep the spray off of your breasts if/when you take a shower.
To help distract him, have dad cuddle him to sleep instead of you; maybe with a sippy or bottle of your milk.
Feel free to check out our website for more information and tips at http://www.nursingmothers.org and have a great weekend!